I have 8800GTs in SLI. Honestly, have not really officially tested (as in full benchmarks) in different games.
I can tell you that it runs games like UT3 and Call of Duty 4 PERFECTLY at max AF and 4x AA at 1920x1200.
At your monitor resolution, I honestly think you might be better off with one overclocked 8800GT. The current boost from SLI is probably only about 15-35% according to most benchmarks.