The true answer? The one you shoot the best.
Turkeys are tough to take down with a bow. The target spot is small. There are literally 100's of broad heads out there and for the majority every one of them will be the correct answer, IF you can shoot them.
Strive to keep groups in a quarter size spot, nickel would be better, or smaller. Learn the anatomy, the target isn't where most would think.
Spring turkeys can be challenging enough, adding the dimension can be though.
Good Luck