Why would he not get the i7 processor? His budget is $2,000, he's going to want to futureproof it as much as possible. And eventually, you'll probably want to overclock. It's really not that difficult, and it's totally worth it.
On the other hand, don't get DDR3. It's not worth it yet, the DDR2 would probably actually be faster (look at the timings on the DDR3 ) not to mention the price difference.
YEAP...I do not want to have to upgade this thing later or for at least 5 years. I guess the MOBO is the most important thing right now...I need one that will support the new beefy technology.