The RockHopper is a pretty bare bones MTB.
But frame size largely depends on the type of riding you want to do. Long swooping corners or bumpy twisty with stunts.
Guys as big as you ride BMXs. But usually not very far.
Go try it out. See if you can extend the seatpost far enough to pedal properly.
Handlebar stems may be changed to stretch you out a bit, but if you go ...



