A
Airsoft J2
Guest
Have a look at the warrior assault holster. It's universal hold type and can be sized for most pistols, it molle mounts so could go on the front. I'd look at the warrior pistol mag pouches too.
I have run both fornyears and theybhave been great, built restful tough and hold mags really well (I've never lost one despite never closing them).
If you don't fancy having them on your front you could also look for a molle belt panel that you slide over any belt. I'm sure you can find the on hueys and tactical kit uk
I'd be cautious about the Warrior Universal and a Sig - the holster pushes on the mag release and you will lose any mags in the gun while holstered.
I'd go for a Serpa or Safariland style holster, either on a belt or on a medium drop and with a leg strap.