Re: do i need sli or not ??
You know you will build or upgrade again after a couple of years. There are a lot of new stuff coming out next year. Socket M2, DDR2, new nvidia geforce 8000 or something, next generation X2's, new motherboards, etc., etc. Never ending. WIth the setup I have now, and yours is pretty similar, it can easily last more than a few years if you're not that type of person that MUST have all the latest and greatest stuff.
*Fact: Microsoft Window's Blue Screen of Death vs Computerforums.org's White Screen of Death. Which is worse?