Lofty,
Got my front brake parts from
http://www.RALDESWWW.RALDES.CO.UK
Go to the blackmax icon on the left and it will load a photocopied page from their catalogue (bit hard to see in places). It will be easier to call them and get a catalogue sent to you i think.
The GpN disks which are plain are about £35 + VAT a pair. Grooved are about £60 + VAT and D&G are about £65 + VAT. I got the D&G ones and have had them for over a year, no scoreing or marking or overheating at all.
Pads, you can get cheapish blackmax ones for about £15 +VAT. I got these to start with and they proved very good, no real fade but i havnt used them on a track. You can get Mintex ones (1144) i think, about £30 + VAT. i will be getting these soon i think.
I also ordered some goodridge hoses (made to order, so about 2 weeks delivery). This helps no end. About £40 i think.
Havnt heard about damaged m/cylinders. I just drained out all my fuild, changed all the parts inc bearings and re-filled and bled system with dot 4.1 fluid. Not sure if i should use dot 5.1 or not. Probably not for winter when you use brakes less harshly. If i still have clio in spring will do another fluid change.
I think BB tuning and Hill power do brakes. Also eurocar parts do ATE grooves disks very cheap. not used these so cant really comment.
Hope this helps mate!