I've got a 256mm brake setup off my G40 that's all ready to bolt on to your car other than the brake flexi pipes. Standard Vauxhall Vectra ones fit straight onto a Polo as they are the same fitting. Kit includes:
Vauxhall Vectra 16v calipers - refurbed last year with new seals
EBC Greenstuff pads - Done less than 5k
High tensile shoulder bolts to fit
Mk2 Golf GTI 16v discs - Done less than 5k
£100 collected from Manchester or postage can be arranged
(http://i.imgur.com/lmICi.jpg)
Still have this setup, but I've misplaced one pair of the shoulder bolts (can get new ones from eBay for about £5).
Price drop to £60 in view of this.
Pm'd
Replied :)