I can't really answer the SLI question, this really depends if companies continue with this whole doubling up nonsense.
I really don't think you need to overclock that, you won't notice any lag whatsoever with those parts.
And as I've said, if you aren't overclocking, you don't need low latency RAM, it's a waste of money. Anyone wanna tell me why he should buy low latency RAM, apart from the fact that "the timings are lower so it must be better logic." I'm just telling you now there will be no difference between 4-4-4-8 and 2-2-2-5 timing RAM at stock speeds.
Intel C2D E6320 / AMD Athlon X2 3800+
Gigabyte 965P DS3 / DFI nF4 Ultra-D
2GB OCZ Gold PC2-6400 / 2GB OCZ Gold PC4000
eVGA 8800GTS 320MB / eVGA 6800GS 256MB
150GB Raptor / 74GB Raptor
2x500GB / 320GB
OCZ GameXStreme 850w / OCZ StealthXStream 600w