Okay after some more research, I'm heavily leaning towards either external bearing ISIS or external bearing Octalink bottom brackets, mated to road double 130 cranks.
So what I need to find is oversized (73mm) exteral bearing bottom brackets that are long enough in their spindles to get the chainline far enough out. Will I have problems?

Should I just go for track 144 and a really long internal bearing bottom bracket with square cranks?