Stryder,
No roundup to my knowledge exists. Here's mine in one paragraph. Basically, you have the reference boards (evga & xfx) and the non reference boards (ASUS P5-NT, ASUS Striker II Formula, and the MSI P7N Diamond.) In my experience, the P7N Diamond is the best high end SLI board money can buy. In brief, the basic issue with SLI boards is that the reference boards can usually OC easily and quite well, yet suffer from long-term reliability problems, especially with NB and RAM burnout. Conversely, the non-reference boards use better components (like solid stake caps and an advanced PWM design) and therefore do not have such reliability issues. However, most are known to be temperamental to work with and are poor OCers. The P7N Diamond is the first board I've seen and experienced which doesn't compromise. It has better components for better reliability, and OCs quite well. Still, there is less community support around the P7N and the BIOS it uses is a bit cryptic around voltages, so OCing will take a bit more work than on the reference boards. However, I think it's well worth the extra bit of work up front for the security that your board won't die in 3 months.
RLymburner,
Putting a GTX card in a PCI-E 2.0 does not double the bandwidth of your card. What PCI-E 2.0 does provide is more bandwidth for cards that can use it. Since a GTX or Ultra can't even saturate a PCI-E 1.1 x16 slot, the extra bandwidth provided by PCI-E 2.0 will go unused. Your GTX card will not perform any better.
You are correct that the 790i will require DDR3 RAM.