Try the Nighthawk Forum (nighthawk-forums.com), but they're not huge on anything non-stock over there. Some "tasteful mods" (read: minimal) are encouraged, but cafes are rare, and bobbers, choppers, etc, are frowned upon. Still, if you tread lightly, there's some good info there, and some fantastic bikes.
That having been said, the Nighthawks have a weird teardrop tank shape with low-hanging tabs, and a cover tail cowel that makes them hard to cafe effectively without major surgery. Not saying it can't be done, but expect frame and tank work.
The 250s are a bit easier than the bigger ones.
