I was quite impressed with the quality of the Naos 3200, even if I had to return it because it was too small for my hands. If you can repeat that quality in a keyboard, with any switch, it will be a sure winner.
Blacks and Browns would be a good combo. If you make one with browns, and one with blacks, it allows two different force requirements as well as a tactile and linear switch. Good way to get your bases covered
If you could offer an MX Clear board, that should sell much better than either. They are hard to find and right now the only option to buy new MX Clears is through Deck, where the board costs $180 dollars.