The new Core 2s totally outperform the high-end AMD chips that are currently out there and are generally cheaper... ESPECIALLY if you're into overclocking at all.
Unfortunately you just missed the boat on DDR2 ram, prices have gone up $50-$100 across the board in the last few weeks.
Arctic Cooling Freezers make for really nice CPU coolers and are only $30 currently.
If you do go with a Core 2 processor, make sure you research the motherboard you end up with to ensure that it will be compatible, same goes for compatibility between ram and mobo. I've had a lot of people putting their own together and wondering why they won't post when it turns out there's an incompatibility between mobo and proc or ram.
Just a few tidbits from a guy who works at a computer shop...
