So, my 2016 fiesta ecoboost 1.0l is coming up for pads and discs. What make do owners recommend/prefer please and where from?

Brembo.  Coated hat line (doesn't rust on the hat)

from Autodoc.

Without removing the wheels, will they be 258mm or 278 mm ,I have drum rear brakes.

Pagid discs also come coated.  They were my preference.

Standard Fiesta size should be 258mm.

1 hour ago, TomsFocus said:

Pagid discs also come coated.  They were my preference.

Whilst they aren't always the cheapest, I've used Pagid discs and pads on all my cars since 2005 ish.

258mm on my rear-drum system as well.

Strangely Pagid are not listed for the Fiesta on Autodoc.  They are on ECP, but 95 quid blimey!

I have had some Brembo coated hats on the Subaru for flippin' years, and they show no sign of wear, which is why I recommend/buy them for other vehicles, incl the Fiesta.

Not saying the Pagids are worse/same/better 🙂

I always use Drivetech, from GSF, never had problems with them.

1 hour ago, orangecurry said:

They are on ECP, but 95 quid blimey!

I have had some Brembo coated hats on the Subaru for flippin' years

The ECP price is per disc, too!  When I fitted the ST front brakes on mine, I found a seller on Ebay that was doing the Pagid discs and pads for similar to the cost of just the discs from ECP. 😮 
When I bought mine, the Impreza that is, it had the original 2 pots on the front.  They're notoriously 💩.  I tried a few different pads, and the Pagid's were the only ones that I felt actually tried to stop the damn thing.  Been using them ever since.

Everyone is different, that's why brake components are a sort of contentious subject.  It's much a case of each to their own as to what they prefer.

ECP are expensive but almost always have a discount code or sale on.  If they're currently full price check again in a week or two.

Also check carparts4less who are the sister company to ECP.  They also sell on eBay as well.

Pair here on eBay for £60.

https://www.ebay.co.uk/itm/325933618681?

I've just checked, I paid £110 for the discs and pads I bought when I fitted the ST brakes.  The same discs are currently £130 each at ECP. 😮 

Try MTec brakes they are quite good on price, and you can have the discs coated as an option. Free post to UK

2 hours ago, mickywrx said:

When I bought mine, the Impreza that is, it had the original 2 pots on the front.  They're notoriously 💩.  I tried a few different pads, and the Pagid's were the only ones that I felt actually tried to stop the damn thing.  Been using them ever since.

Off topic, apologies to the OP

I had a Prodrive Impreza, but we now have a Legacy Spec.B - I tried every brake pad under the sun, but found Hawk HPS were the only ones that worked really well.  They've lasted very well, and on the Brembo discs.

Hi There, Just last week installed Brembo pads on front comes with bolts and anti rattle shims. Got these from ECP keep an eye out on discount codes.

EBC discs are coated and is what I use. The painted/coated bits seam to resist corrosion quite well.