I have to admit...I am a Primos aficionado. And since this is only my opinion, here it is.
Primos Power Crystal Slate call w/ Purple Heart Wood and Carbon Striker
Primos Box Cutter Box Call
Various Primos mouth calls....whatever is easier for you to use.
In Spring Gobbler Season of 2004, I wasn't able to get a gobbler to yelp, as many people in Susquehanna County in Pennsylvania, but I did manage to call a very vocal hen in within shooting range. Let's say if it was the Fall Season, I would have been walking out of the woods in the morning with a hen over my back. I was using the Power Crystal Slate call. You can go to [www.primos.com] for more information. You can hang me or praise me for my opinion, but that's what it is.