Zwickey Deltas will work fine. I'd stick with the two-blade though. Turkeys are tough to penetrate for two reasons. Their heavy feathers and feather quills are tougher to get through than deer hide, IMO. But the big reason is because they are relatively small and physically light vis-a-vis a deer, for example, they tend to move with the arrow at impact. The arrow hitting them pushes them a bit, which expends some of the arrow's energy outside the bird and reduces penetration.
Though I've killed a few birds with Zwickeys, I've gone to Woodsman 3-blade heads the past several years. Good mechanical advantage and penetrate very well for a 3-blade head, and not too much width for a 40# bow.
A pop-up blind and decoys will increase your chances tremendously.
Good luck. Turkeys are a hoot. Or is that a Gobble.