I mainly considered Dell's for the warrenty and occational good deals. But I'm certainly not a newbie to comptuers seeing as I built the comp I'm using now and it's still working just fine
As for OCing, I've never been much for that. Anyway, I don't think they even made the Athlon64 at 2500+ :P
9800XT...I considered dropping down, but if I can fit it into my budget, I'd like to be sure I won't have to upgrade for a while.
Finally, HDs... I considered using a raid system, I guess that would really help out performace. I shall look into that