My nearside coil spring has been snapped for about a year now so it's probably about time I do something about it!
Do I just buy OEM or are there better options? I don't wish to overcomplicate it with fancy adjustable coilovers.

Really all that is damaged is the 1 coil spring, obviously I would want to replace both sides though.
As the car is currently at 102k miles I thought maybe it would be best to replace the full assembly?
Or should I just buy coils, top mounts with bearings, and dustcovers (they are deteriorated)
I would need to pay a shop to compress the springs on for me as I do not have that tool, also the danger side of it is not worth the cost trade off for me.

At this point would it just be worth replacing the full assembly? I'm wanting to put another 50-100k miles on this car and god knows how far the shocks, mounts or bearings are from failing. I have no idea how many miles they are rated for.

-P.S
If your suggestion is for aftermarket then what brand do you recommend?
If OEM then where is the best place to order them?
I do not want to put poor quality or fake parts on as I don't wish to do this job again on this car

If you're paying someone else to do the whole job, might as well just do the one spring for now.  No point spending twice the labour having both sides done.  It's an MOT fail so you won't be able to leave it much longer.

If you want to upgrade I'd say Eibach pro springs with Bilstein shocks...but that gets expensive and unnecessary if you want to stay OEM height.

I've found shocks tend to feel worn before 100k, but they'll still 'do the job' for another 50k or more.

35 minutes ago, TomsFocus said:

If you're paying someone else to do the whole job, might as well just do the one spring for now.  No point spending twice the labour having both sides done.  It's an MOT fail so you won't be able to leave it much longer.

If you want to upgrade I'd say Eibach pro springs with Bilstein shocks...but that gets expensive and unnecessary if you want to stay OEM height.

I've found shocks tend to feel worn before 100k, but they'll still 'do the job' for another 50k or more.

I am going to install them myself, its just the compressing the spring side of things that I do not wish to do myself.
If I was to buy it unassembled then I would need to take it into a shop for them to assemble the strut for me to then fit myself.
That's why I thought it would be easier to buy a fully assembled strut.

I'm not too worried about the MOT for reasons which you can assume. 
Regardless of that fact I still wish to sort it. I would prefer to do both sides as I always do with brakes & suspension components!

I think I'll just bite the bullet and replace the shocks at the same time. Honestly I have bad luck, knowing my luck I will end up needing to do the job twice when a shock fails 15k miles down the road.

If you can take everything else apart and refit thencompressing the srping won't be too hard for you, just get some decent spring clamps. I have a Draper set with 3 clamps (always thought 2 was a bit dodgy on Mondeo springs). 

Yes, yoiu might as well change the shocks while you're at it. I changed my shocks at 78K miles after needing new top bearings.

Ah, I see what you mean now.  I don't think you can buy fully assembled OE shocks & springs.  Does make sense to do both sides of you're not paying for full labour.

Having said that, I've assembled a set of Eibachs & Bilsteins without 'properly' compressing the spring.  Just put my weight onto the top mount (all 55Kgs!) and that was enough to get the nut on top.  Then just gunned it tight.  I wouldn't recommend removing a top but without proper compression though.

1 minute ago, Frembrit said:

If you can take everything else apart and refit thencompressing the srping won't be too hard for you, just get some decent spring clamps. I have a Draper set with 3 clamps (always thought 2 was a bit dodgy on Mondeo springs)

Honestly I'm just too scared of damaging something in the near vicinity or worse taking the top half of my head off!
I would be willing to use good quality clamps but for the price of them I think I would just pay a local shop £20-30 to assemble them for me!
Trust me I'm a pretty clumsy person lol 

If the shocks not leaking I wouldn’t replace it , yes it might start leaking in 15k miles time,but something else might happen in those 15k miles (eg engine failure, theft etc) and then the money on the shocks was wasted.  There’s pros and cons either way .  If mine I would just replace the one spring if that’s all that is broken/worn. A lot of people say you must always replace springs in pairs. I don’t heed that advice. 

If you’re just going to replace the 1 spring you won’t needs compressors, the springs already broken and you should be able to get the nut back on just by pushing the spring down.

I can’t assume why you’re not worried by the MoT.

Done well having a broken spring for a year.

 

4 minutes ago, MarksST said:

I can’t assume why you’re not worried by the MoT.

Done well having a broken spring for a year.

 

Wasn't sure if I'd misread that.  I had a snapped spring for all of about 10 minutes before it pierced the tyre.  Luckily doing less than 30mph on a dry road.  Certainly wouldn't be leaving it once I was aware.

1 hour ago, MarksST said:

If you’re just going to replace the 1 spring you won’t needs compressors, the springs already broken and you should be able to get the nut back on just by pushing the spring down.

I can’t assume why you’re not worried by the MoT.

Done well having a broken spring for a year.

 

Lets just say that some people are more lenient than others?

Yeah it’s basically just the very bottom part of the spring that has broken off. If I was to guess I would say it’s probably about 6” worth of spring.

You can barely even notice it when driving, my tracking goes very slightly to the left but that’s about it!

1 hour ago, TomsFocus said:

Wasn't sure if I'd misread that.  I had a snapped spring for all of about 10 minutes before it pierced the tyre.  Luckily doing less than 30mph on a dry road.  Certainly wouldn't be leaving it once I was aware.

I suppose it depends how close to the middle that the spring snaps? 

20 minutes ago, CursedBones said:

I suppose it depends how close to the middle that the spring snaps? 

I guess so.  Once the tension is reduced the spring can move while extended, so it can 'jump' out of the spring cup after a harsh bump, either cutting the tyre or the brake hose or the ABS wiring.  Also depends on whether it breaks squarely or leaves a sharp point like mine did.  It's one of few MOT fails that are genuinely dangerous.  Not one that I'd expect a tester to ignore tbh.

12 hours ago, CursedBones said:

Let’s just say that some people are more lenient than others?

 

Oh, one of that type of tester, one who can turn around when/if something goes wrong and say, “it was ok when I tested it”, everyone else can deal with them knowingly passing an unroadworthy vehicle. 

If you were anywhere near me (Cardiff) I would've assembled them for you, I do not blame you at all for not wanting to use widow makers, I've had 1 too many close calls with them so bought a Clarke strong arm. As others have said, if you change both shocks, assuming they're good and then something else goes wrong, you've wasted money replacing working shocks that could've gone towards your new issue. You could always take the shocks off, have a good look at their condition and then make a call from there.