My suggestions to stay with 3" rims or less. This avoids chainline and chain/tire rub issues. If you could send me an email addy, I can send you a dimensioned drawing of a Project 346 Basman, which is one of the most sought after frames. I personally own one along with several other bikes. It will be the last bike I would ever sell. Minimum of 4" of ground clearance so it is truly ridable, w/o dragging issues. Shimano Nexus 3-speed is a very common rear hub. 30 degree head angle is good. Remember, you want to enjoy the ride, not stress the workout from poor handling or excessive weight. Sorry Im all over the place with my thoughts.