DX9 vs DX10

So here is my dilemma. I can buy a better-spec video card that is DX9 capable or a DX10 card that is less capable (via the specs.) Which is a better idea? I am having trouble finding a 512MB 256-bit DX10 card with at least 20 pipelines. Can anyone shed some light on my dilemma? The DX9 card in question is the MSI NX7900GS-T2D512E-OC GeForce 7900GS. Does anyone know of a card that is of comparable price and quality (performance) that is DX10 capable? This might be a dumb question, but can the afore mentioned card run DX10, or is it impossible? Thank you so much for your help!!!

 

Again at newegg nvidia 8800, but lots of loot

http://www.newegg.com/Product/ProductList.asp?N=2010380048+106791921&Submit=ENE&SubCategory=48

http://www.tomshardware.co.uk/2007/05/14/r600_finally_dx10_hardware_from_ati_uk/



http://www.nvidia.co.uk/object/may_gpu_uk.html

http://www.pcplus.co.uk/news/home_n..._drivers?cid=OTC-RSS&attr=PCPlus-Standard-RSS