Yeh your going to be looking for a server board im afraid... there are heaps around and they arent all that much more than normal desktop boards... Mainly Intel, Asus and Tyan are the bigger server board makers.
I don't recall how much memory it had, but as a repair tech I was having an argument with the owner over it.
The system kept getting memory errors with all 16 slots filled but worked fine with only 8. All the memory tested clean. Took me forever to finally agree to allow me to swap 8 higher capacities SIMMs for the 16 lower capacity SIMMs.