I'd suggest either the Magnum .46 or the Thunder Tiger, both mentioned above. After about 2 tanks of break in the Thunder Tiger is very easy to tune. Just don't hammer it for a couple more tanks of flying and you should be good to go.

I have 3 Magnums that I've bought used and all have been exceptional.

That said, you can't go wrong with an O.S. if you are willing to spend the money.