hmm, I currently have the evga 780i SLI ftw board, and it is stable enough with my q6600 OC @ 3.3 ghz. It from what I hear, nvidia chipsets have less issues with dualies. Alternatively, you could get the 750i ftw, which is also supposed to be popular, and pretty good too. It really depends on how far you need to OC though.
Alternatively, you could get a gtx 260 or 280 and sell your 8800. If you must do SLI, the evga 7xxi ftw series are pretty much your options, and they are pretty good IMO, and should get better with Bios updates.