I'm not sure what you mean by "chest rig"?
Do you mean like a tanker rig? Or a shoulder holster that rides low/across the lower torso?
I'd see the websites for Mernickle or El Paso Saddlery for outdoor styles. The Bianchi HuSH field holster may do well. It was designed & T&Eed by noted outdoors writer & gun expert; Dick Metcalf.
The UM92/M12 milspec holsters from Bianchi may do well for semi-auto pistols. They are nylon fabric but come up in many colors & can be converted to different methods; cross draw, SAS-leg carry, tanker, shoulder, etc.
Bianchi has the US armed forces contract for the M11 & M9 sidearm holsters;