yep the one that allows the motor to turn 6000 rpm at WOT with a full tank of fuel and a medium load. call Lund and let them suggest but be aware that you may have to play with props and engine heights to get it right
Yamaha makes a decent stainless, but I think Merc props are much better and there's alot more variety. You need the Yamaha hub kit from Merc to go along with the prop. The hardware that fits the Yamaha prop is different.
