Im on a bit of a tight budget at the moment! Seen EBC Rear discs on Ebay for £28 plus postage!! Also will be re-newing handbrake cables, MOT due, need new discs on rear as looking very rusty round the outer edges of disc! Anyone bought rear discs this cheap? Am i buying crap and most likely to be changing them in the not to distant future?

If your fitting new discs then budget for new pads too.
There is little point in fitting the old pads to new discs as you will be effectively reducing the friction surface area where the pad has taken the shape of the old worn disc.

It would probably work out cheaper buying from Alternative Autos and getting the pads, discs and handbrake cables all delivered together.