First build question; gaming system should I SLI 2 gig or get one 4 gig graphics card

[G+_Joel Cooper]

First build question; gaming system should I SLI 2 gig or get one 4 gig graphics card. I am using a crosshairs 5 formula z mother board, AMD fx 8350 processor.

[G+_Vincent Panico]

My first build I had SLI power supply 650watt and Asus MB SLI ready and 8500 GT Nvidia 4gig ram