Hey red,
I have two complete A1200 one with a Blizzard 1260 running OS3.9 and the other with a Microbotics MBX1230 XA running OS3.1, I had a loose A1200 board which was in this D-Box tower that I was running with my Blizzard 1260 for a while, waiting for a PPC accelerator. The main board went bad and I sold it for parts and was planing to take one of my A1200 and convert it over, but just have not had time to.
I have a lot of money wrapped in these items, but I rather sell it to someone here on a.org then ebay it out. It sounds like you may need another A1200 main board too, and accelerator?
As for the difficulty, if you are pretty good with computer assembly and adding and removing components you should not have an issue. Plus, Elbox has step by step instructions for building the tower online, and I also have the manual as well for all of the items. What were you looking for as far as an accelerator? 060, 030?
Mike