The guillitine is a great one for turkeys but you need to make a head/neck shot. The new head from Magnus is similiar to the guillitine but you can take a body shot with it.

I would say if you are accurate with your deer heads, then just stick with those. One key is if at all possible you would like the arrow to stay in the bird making it tough for them to fly away. You could think about lowering your poundage a bit or using something I have used in the past. Its called an adder point (Cabelas has them) Its basically a barbed collar that sits behind your broadhead and creates drag as it goes through the bird increasing theodds it stays in.

Study a turkey vital diagram as they are a little deceiving.