Haven't you always WANTED to stick a turbocharged V8 into a Honda Civic?
As for RAM, it's so cheap now, it's insane. I have four 1GB Crucial Ballistix DDR2 modules I'll probably let go for a song, since I just purchased two 2GB G.Skill's for $45 with free shipping.
Maybe a triple-core Phenom II makes sense (assuming AMD releases them), or a budget version will come out. Phenom II outperforms Phenom by enough that I'd probably skip Phenom altogether now that II is out. Power consumption is also lower.
Intel Q9450 @3.2GHz, Gigabyte GA EP45-UD3P, 4 x 2GB G.Skill @4-4-4-12
Antec P160SW case (modded), Xigmatek 750w PSU
3x 500GB (RAID-5), , OptiArc 7200S, ASUS E818A3T
Creative X-Fi XtremeGamer, Hauppauge HVR-1800, Radeon 4890