Like Mike said do your research and you will find answers to your questions. There are many variables to the way a call sounds. And my measurements maybe slightly different than yours. But a general answer is your sound board is usually about two sound boards thickness under the surface. And a good starting point on bottom depth is a 1/8" pedestal. Many other things will change the sound. So just experiment. I made alot of scrap before my first good call. Good Sharp chisels is also a must. And I'll second cherry wood. I love cherry sound and it's ease to work with. But I suggest spending hours and hours and here reading old threads and THO. I'm no expert at all but passing on what I know. These guys have helped me along the way several times.
Sent from my SM-N920V using Tapatalk