The board does support Tualatins, and the chipset does support 3 dimm slots. All I would be changing is the socket, and that would be to an identical one.
The dimm slot is a possible addition; assuming it is connected(I had not examined it, I just assumed it was).
BTW, I do have some soldering experience. I have only done it with wires, but I am fairly proficient with a soldering iron.