take it to a motorcycle shop. they could balance it on their machine because it looks kinda like an axle on a bike. Just explain to them what you are doing and they should be able to make it exact for a few bucks. The tire machines they use for car and truck tires would not work for this.
u could try i motorcycle shop but i think its to wide for that.....if you can get really lose bearrings to put it in you can just do it yourself by hand... thats how i will be doing mine.
what are you useing for your clutch? is it a torq-a-verter?
Once I bolted everything down tight it reduced the wobble a bit. With 1000 ft of line it should self balance the rest I think. Check it out... almost done: