has any one carried out a rear disc conversion on a 1.6 petrol focus saloon, or any focus variant for that matter?

if anyone had done it what parts were involved? i know it'll want new hand brake cable, callipers, hubs aswell as the discs and pads

I have done it on a mk1 1.6 hatchback.

Probably a very similar job to the mk2.

You will also need new hoses

what were the cost involved? and was it worth it?

It's worth it for looks and after long periods of hard braking, drums tend to get very hot and fade - and as i found out, wrecked a set of shoes. After fitting the discs and doing the same hard driving and hard braking i had no issues. Disc brakes are much easier and quicker to service or replace parts compared to drums so thats an advantage too. But many believe the rear discs are more powerful than the drums, standard size discs and calipers offer about the same as drums and you want notice any difference.

It depends on how cheap you can get the parts but expect to pay 200-300 quid anyway.

A set of braided hoses make a huge difference too, keep the pedal a bit firmer