You are halfway on the right track!
Good call on looking at NForce4 chipsets. They seem to be really good performers all around (not just for gaming).
Perhaps you should get a mobo that uses the NF4 chipset, but doesnt have SLI.
Perhaps something like the MSI K8N Neo4-F Socket 939 NVIDIA nForce4 ATX AMD Motherboard - Retail
It's not the best overclocking motherboard, but it seems like a good buy for what you get.
It'll give you a PCI-E x16 slot, as well (in case you already have a vid card you are using).
As for AMD vs Intel...Dont make a thread saying something along the lines of "AMD vs Intel" or else it will get locked. To compare the 2 CPUs look up benchmarks on www.tomshardware.com
and also look at the AMD vs Intel thread at the top of this thread.