1) Besides the graphics card, would I have any other reason for another PCI-E slot?
2) Budget would be $700-$800. Main goal is to have a computer that will last 8 years, and keep up the times (software upgrades). I multitask a lot, have lots of windows open (20!). Will have a mix of excel, word, internet, antivirus, photoshop running at the same time. Also, I'd want to play starcraft2 on max levels (with all other programs off). That said, though the i5-760 may be "enough", if I want to think ahead 8 years, might as well go to i7, right?
3) i7-870 is the same price as the i7-950 at microcenter.com. Should I pay more for the mobo and RAM to get a more future proof system (relative to the 870)? It would also be the difference between 4GB and 6GB ram.
2_hmm,no one can tell you if your PC lasts for 8 years or not but the difference between i5 760 and its i7 equivalent isn't noticeable in almost all tasks
3_It depends on you, but 4GB doesn't have a lot of difference with 6GB.(at least for now)