Did it myself. Got the processor on ebay for about $150, new motherboard from newegg.com for another $100, installation took most of an evening including a full reinstall of Windows, which I prefer to do when changing the motherboard.
Newegg is the best. I just did the same thing last month. I went to an nforce2 chipset and AMD 2500+, with memory for around 200. We tried an nforce chipset mobo when they came out and we'll never go back to VIA (or others) with the AMD chips.