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 Type F Fullsize .40 S&W | Beretta 92FS 9x19 Para | Beretta 8040 Cougar Type G .40 S&W | Rock Island Armory GI 1911 .45 ACP | Sig Sauer SP2022 Stainless 9x19 Para | Sig Sauer P6 9x19 Para | Colt Python 4" .357 Magnum | Colt 1968 Det. Spec. .38 Spc. | Ruger LCP .380 ACP | Daniel Defense M4V1 5.56x45 | Alpine M1 Carbine .30 | Steyr M1895 8x56 | Ruger 10/22 .22LR |1943 Izhevsk Mosin-Nagant M91/30 7.62x54R | Remington 870 12GA