i5 760 @ 2.8Ghz
Asus P7P55D Pro
Corsiar 450 PSU
1 x Ocz Vertex 2 60GB
2 x Segate 250Gig (Raid 1)
1 x 4gig G.Skill PC12800
1 x evga 8800 GT
Can my PSU handle SLI on two x 8800?
My monitor only runs at 1280 x 1024 resolution, it is worth it to get 2 x 8800GT?
And what kind of performance improvement will I see if I do go SLI?
Well... I recommend just not even getting a new one, sure you could get one off of Ebay cheap but the performance increase from 8800GT to 460 is pretty large. I mean the 460 OC'd even just a bit could reach the 470's performance. Plus the 460 is so cheap now, it'll be a great buy!
The cheapest Newegg 460 is a Galaxy one for 135$ and 115$ after MIR.