What video card should I go with?

I currently have an EVGA GTX 460 but want to run two video cards. Problem is my motherboard doesn't support SLI, it does support crossfire though. So, what video card should I buy two of? I want each card to be on par or a bit better than the 460 but want to remain price effective. Also, is a 750w psu enough to run two cards?|||if your motherboard supports Crossfire, then buy an ATI Radeon card, go with HD6000 series, it's a beast for extreme gaming, but if you don't want to replace your old card, buy a new mobo.|||Please take ATI card. Its the best solution as it seems to me.|||if you have crossfire, use ATI video card