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.
Beretta PX4 .40 S&W - Colt 1968 Detective Special .38 Spc. - Ruger LCP .380 ACP - Daniel Defense M4V1 Carbine 5.56x45 - Ruger 10/22 .22LR - Remington 870 Express Tactical 12GA - Mosin-Nagant M91/30 (Excellent) 7.62x54R