Motorcycle Repair: speedo drive unit, wheel hubs, spacers

Question
 i'm having a rolling frame built with a 41mm wide glide front end, with a 19" wheel.i want to have a front speedo drive 2:1.  the catalogs i've seen list  only two early model drive units for a 19" wheel, but list it for narrow glide.    
 don't these speedo drive units mount up to the wheel hubs, and also isn't the only real difference between a narrow and wide is the tree.
  can you please tell me what speedo drive unit i can use, and what hub and/or already assembled preloaded 19" front wheel to use.  thank  you  

Answer
You can buy a already build front wheel for your project in the 19". In order the determine what drive unit to use will depend on what year wheel you use. the wheel you pick can be any that fits a harley. The drive unit is also used as a spacer for the wheel bearing. the difference between wide glide and narrow glide is the width of the forks. So you need to get the wheel and the right drive unit and then do some measuring for spacers to fit it inbetween the forks.
Good luck and happy riding
Mike