Chris,Whoops, somehow I'd read your reply to Tom Uban but completely misread what it was you were asking by skimming over what he said.
Anyway, as far as SBC6120s go, I don't know of anyone "building them", as in a ready built system, but blank PCBs are available on chipkin.ru if you can tolerate waiting for Russian Post.
As far as I know RetroBrew finished their run, but as the Gerbers are GNU FDL'd so you can have PCBs made anywhere.
-Tom
