The 660ti would be a very solid choice for gaming at that resolution. Dunno if you'll be able to hit 60fps constant maxed out but 60fps average maxed out or almost-maxed should be doable.
Since you don't already have a gaming rig, IMO there's no point waiting around for the next gen. We're still months off from new cards. Looks like a pretty nice midrange build.
would 2x 7770 in Xfire be better?