How well does the belly band method secure safeties and triggers as compared to a holster? As long as it's secure, the P938 fits well. If not, you might want to go for something with a longer or heavier trigger. Sig P239 is a nice gun but kinda big and not great capacity. I also liked the CZ PCR suggestion, or a CZ RAMI.
16 Pistols, 5 Rifles, 1 Shotgun, no time to shoot them