I have an 8800gt and I wanted to upgrade to something more powerful. I wanted to keep the upgrade under 350. I like gaming and want the most powerful/cost effective option for that price. Must be a canadian retailer. I was looking at the GTX 470,480, 570, or 6950, 6970.

I have an X38 board so I was wondering if it could support PCI-E 2.1 as well.