Modular grip frame would be a very good thing. Thin, thick, short and long could accommodate a variety of uses, from carry to high capacity shooting games and everything in between. A lot of sales potential in that.
I'd probably keep the caliber changes to a minimum if possible, i.e. all 9mm, 38 variants, Then a seperate model for the 40 and another for 45.
Sell more guns, if it's a for profit business, and the 9mm sized guns could probably be smaller/slimmer for carry if needed.
Besides, many pistol shooters, need an excuse to buy another gun, don't take that away from them.
I doubt meeting half way for the single action shooters would work well. I'd have two seperate models or not have a single action trigger, given your preference.
Good luck
I'd probably keep the caliber changes to a minimum if possible, i.e. all 9mm, 38 variants, Then a seperate model for the 40 and another for 45.
Sell more guns, if it's a for profit business, and the 9mm sized guns could probably be smaller/slimmer for carry if needed.
Besides, many pistol shooters, need an excuse to buy another gun, don't take that away from them.
I doubt meeting half way for the single action shooters would work well. I'd have two seperate models or not have a single action trigger, given your preference.
Good luck