I have an AMD 5600+ X2 with 2 Gigs of 800mhz ram on an nForce 570 Ultra mobo. I am thinking of replacing my 7950GT and am wondering 2 things: a) Do I need to limit myself to a PCI-X16 1.0 video card or can I get a 2.0 and not have issues? and b) what would be my best choice for a video card...