If you already bought the rear friction drive assembly from bikemotorparts.com, try to mount it UP FRONT.
This will give you more loading space in the rear.
Install motor mount onto front fork. Note that the drive assembly mounting holes will be REVERSED and the engine is still on the left side.
Install your bearings,collars, roller and rear(now to be front) support struts onto your housing. Position housing next to motor mount. if everything aligns and roller contacts tire well, then drill the housing for NEW motor mount and support holes.
Then fabricate two endplates that adapt the support rods to the front fork dropouts. These plates are rectangular, about 1" x 2" size.(Or buy these from Staton.)
Find a short throttle cable, hook up kill switch, adjust the roller/tire contact and you're done.
Your bike's steering feel will be sluggish at slow and walking speed. What the heck, your loaded bike will feel awkward anyway.