The problem with AMD and SLI is simple.. all SLI capable boards for AM2/AM3 use NV chipsets, and they basically all suck. They run hot, don't overclock as well as AMD or Intel ones and are a bug-ridden PITA to deal with. I once had a 780a (M3N78-HT) and let me tell you this: Never again

Only decent way to go SLI these days is with an x58.