Nice job, Lucian! I can`t make much sense of the text, but the bike is beautiful.
Jay35, I imagine you`ve already seen Sheldon Brown`s homebuilt pages, and I think I saw a reference to them in one of the links abopve, but just in case- make sure you cruise his site. I thought Michel Gagnon had some info too, but I can`t seem to find it.
Also, Tim Paterek has a chapter devoted to tandem specific considerations in his very helpful Paterek Manual for Bicycle Framebuilders.