Video card for vista

So i have a Pentium 4 CPU 3.00 GHZ 1GB of RAM. ROFL i am a noob when it comes to these type of things(posting pc specs). Dont blast me if that didn't provide you with any info. Anyway i want to upgrade my pc to VISTA.

Thing is i want to use the DX10 features, so what are the GPUs/ Videocards that run directx 10. I saw 8800 GTX but thats over $500(could use that to buy myself a ps3...lol). TOO much. Any help is much appreciated.

help

I hate to say it, but I don't think you'll be just buying a new gpu. Probably have to get a new mobo, which means new RAM, Processor, and GPU (and probably a psu to go with it)