I dragged all my stuff upstairs, and set it up. I disconnected everything, pulled out the motherboard, pulled out the chip, and found the thermal paste was GLUED to the CPU, preventing me from putting the CPU onto the new motherboard. Luckily, a little snooping around the web showed me that applying a hairdryer to the heatsink (not the CPU, GAHHH!) until it was too hot to touch and then slowly twisting the CPU off. It worked!
Next, I affixed everything best I could, and booted the machine up with the minimum I needed to get a screen, and was delighted the ASUS logo showed up. Then, one by one, I tested each component, weeding out the bad from the good. I found that my "broken" hard drive worked, and with a test floppy from the web site of the fine people at Western Digital, I found that the drive was perfectly fine, and still had valid data! So I decided to try and see if I could rebuild the RAID5 array as a whole later on.
$120 AGP Card? Dead. $5 NIC? Dead. A $60 512mb stick of RAM? Dead. It seems to make sense, since all those things were near each other when the system died.
Next, I swapped out my CDRW with a new CD-DVD-RW, and that worked. The new RAM worked. I booted into my old OS, and rebuilt the array, ran fsck, and wala! My data was back, and Tripwire didn't give me errors. If I understand this correctly, this could mean all my data is fine, and I have a spare 80gb drive to boot.
I thanked the Gods that be.
Now I am running a full system diagnostic and running an rsync to my new external WD Hard drive.
So far, everything is working fine, and with its Antec power supply, I hope it lasts a long, long time.