Currently, you only have two options for AM3 / SLI
is the 980A chipset, which is pretty much the last Nvidia chipset motherboard. These are the boards to recommend, in your case.
I don't believe that Nvidia is planning on releasing any more motherboard chipsets. With the release of the X58 allowing SLI/Crossfire, it pretty much killed the Nvidia chipsets. Plus, they were pretty much always a buggy chipset to a point.