Are you looking for finished product of 16 lbs. boneless, after smoking?
Your boneless yield will be about 40% of raw bone-in weight. You have the skin with fat, ribcage and keel bone to remove, that will be about 50%, then cooked shrinkage. Are you going to skin and bone them out first, or after smoking?
You will need about 35 lbs of raw weight, about 10 breasts. The skin and fat will weigh the most.
You can counteract some of the shrink by brining them, either with or without cure, putting moisture back into them first before smoking/cooking them.
If I am erring, it is on the side of too much vs. too little, as the plumpness of the breasts and if they've been injected first, etc. can play a big part in it. Let me know how it comes out!
By the way, if you would so kindly stop over to Roll Call and introduce yourself, then we can properly welcome you!