I'm an AMD guy, but I've always liked the underdog. It's true that an Athlon 2600 is running fewer Gigahertz than an Intel 2.6, but I will say that every benchmark I've seen says that they are the same. It will pull up programs, code MP3's, zip files, everything just as fast, and cost about half the price to buy. I think that you're right there at about 2600 too, the AMD is about $100 there, and the others start to ramp up pretty quickly. I like the new Barton cores as well, faster FSB and less heat produced than the older T-breds.

I also like the VIA KT400 chipset, mine works fine and cost less than any comparable nForce board. On brands, my best luck has been with MSI and Gigabyte, and I've had nothing but trouble from Abit. Gigabyte's my favorite - great support on things like BIOS updates, etc. (you can even do it over the web if you can believe it). I have a 7A-VXP with RAID 0 & 1 built in (which I just use as IDE channels 3 & 4 so I can have up to 8 "things installed", it's got built-in firewire, USB 2.0, Ethernet, 5.1 sound with optical ouput, etc. and was only about $100.

For RAM, if you go with AMD - any chips running their 266 only need PC2100 RAM (both run at a 133 multiplier), anything faster ont he RAM will just be dumbed down to the slower speed to match the chip. If you get a 333 Barton core, you would need PC2700 RAM (both at 166), and the new new XP3200 runs at 400 (needing PC3200). Where I'm going is - just don't get any faster than you need. Corsair, Crucial, and the Kingston Hyper-X line are all good names, and I've had great luck with Buffalo and Dane-Elec too. It seems to be less about the name on the RAM, and more about the chips used on the stick itself.