Get what Zak aka Goldrush suggested. I have that one, but the turbo version, and its as smooth as butter, but when you want it to hook up, it will engage hard if you like!!
I've hammered mine, and I've yet to get it to slip. It will stall the motor out, before the clutch will slip.
Just make sure you get the 0.026" step put in the flywheel, and you will be golden. (iirc)