Just make sure your RAM has a spec voltage of 1.8V or 1.9V -- any higher and your're just buying lower-quality overclocked RAM. Stay away from OCZ RAM, as they have more compatibility problems.
I'd strongly suggest going with an Intel chipset board (e.g. P35) and not go SLI. SLI is almost never worthwhile, as the next batch of video cards will include a single-card solution that outperforms your SLI.
The 9600gt in sli is very good so your wrong there, however I still might wait a couple of weeks for the ati 48xx series release.