looking for: hardcore mobo mods (many cpus)

[Titan]

Just wondering if there are any good resources out there on how to basically construct your own motherboard, by modding existing parts. I know this used to be done with old pentium pro CPUs so thet could fit multiple CPUs in one system. And the knowledge required is probably way out of my league, but I may be able to find a motivated computer engineer to help me on a project if I have some good information. I was thinking how cool it would be to mod an 8-way xeon using the old 550 chips with 2mb of cache, since they are so cheap now. But octal boards are nearly impossible to find.