Whoa, slow down there neighbor.
We've got some beautiful weather here for a few days now but you know what's coming soon....unless you're heading south....so even if you ordered today with shipping time and mounting it might take a couple weeks at least....just in time to be facing winter.
Chain drive is more efficient. Staton chain drive is bullet proof, a little heavy, and a bit of work to get it mounted right, relative to the particular bike one is using. It costs more.
Friction drive has some limitations......wet surfaces and IMO off-roading not as good. The Staton FD is again, bullet proof, lightweight, and a snap to mount.....one real nice advantage is you can swap to another bike in a half hour. They are pretty sweet, pull hills real well. Cost less.
The Mits engines are very nice, good power, dependable and 2 stroke, so for me, a little raspy.
I have both Mits and Robin engines I swap between Staton and bikemotorparts drives. If you were ever out my way I'd let ya take a spin.