Why? The assumption being I won't eventually upgrade to sli?
Generally speaking, you'll buy more performance buy buying a single "big" card than by pairing up two cards. Also, there's hassle getting the drivers and profiles to work well. That hasn't been as true lately, but I don't generally recommend it unless you have firm plans in the near future (within a year) to upgrade.
Beyond 1-2 years, you will probably get better performance for your dollar by selling your old card and buying a newer card to replace it than by buying a second old card. SLI/CF scaling is only around 60% for the second card.
is this a gaming pc because if it is there is no need for quad core unless your a multimedia pc and going to be doing a lot of multitasking
if it is go with the E8400 wolfdale sorry no link
90% gaming, but it will handle some encoding duties
I picked the q6600 over the E8400 because it can easily OC to 3.2 and I've heard people get it stable closer to 3.5. While I know the E8400 can get close to 4.0, I'm essentially betting that future games will take better advantage if the Quad core. Plus it's only a $15 difference.
If I'm missing something, I loved to hear where I'm wrong! That's the point of this topic!