This is an updated version. I have taken into account the advice from others on the server. The GFX is being bought from else where, a Sapphire ATi Radeon HD 4830 512MB GDDR3.
EDIT: Updated to include OS, Fan and DVI to VGA adapter. Im doign to use a old monitor until around feb 10
its turned out to be around £400 for 4gb ram, 512mb ddr3 GFX card, duo core 2.33ghz, windows 7 premium, 500gb HDD, 500w PSU and a cheap case. Is it worth it?