Re: debating running SLI
I don't think it's worth SLI'ing two 7600GTs. You would be better off buying a single 9600GT or 9800GT. Two will 7600s will not be as powerful as a single 9600 or 9800 and will consume more power.
If you are running two games at once, It may be beneficial for you to get 2GB more RAM for your system. Even non gamers notice speed improvements with 4 gigs.
The Core 2 is very good but if you overclock your CPU, you will likely not need a new CPU. But if you want to you can go with something more powerful, you could go with the E7300 or the E8400.