Another whim led me to buy an AMD Socket A motherboard off of ebay for the low low price of $28. It has some things on it that definitely won't work such as the built-in networking and the DDR RAM slots, but I am holding out hope that the board is either working enough to POST, or repairable.
Update: A friend of mine mailed me a care package of parts that would suit it well, including three CPUs, two GPUs, a heatsink, and some DDR memory in case I manage to fix those slots after replacing/installing some capacitors. I have updated the part list accordingly.
The CPU, an Athlon XP 3200+, which is the fastest possible Socket A processor, also seems to be running at half of its rated clock speed for some reason, which I assume is related to the frontside bus. I don't know if using DDR memory would fix this. The other two CPUs he sent were a 1GHz K7 Athlon, and a Sempron 2400+. Of the two GPUs he sent, the ATI Radeon 9600SE is working perfectly, and the Nvidia Quadro 4 is displaying garbage intermittently. I have been told it is potentially fixable, but it would need to be recapped, as many of them have bulged and begun to fail.
And of course, after all of this is sorted/when I have some money again, I need to get more parts for it. A case, power supply, and media to put things on are of course going to be paramount. A solid state alternative to an IDE hard disk is definitely going to happen, and I will most likely need a CD drive of some description.
Current Parts Obtained