I'd def pay extra bucks for one fully put together with pouches etc
You could offer 2 or 3 different configurations for one to pick from.
examples
Configuration 1:old school Infantry setup: 1 canteen pouch w/ canteen on each side, plus a couple of ammo pouches on both sides in front (for those who dont wear a camelback or who want their chest rig as a slick back for backpack addition.Plus maybe a Glock knife or something right behind the right side canteen.
Configuration 2: A modern interpretation 1 pistol holster on right. a couple TACO pouches on left and an admin pouch or two .
Configuration 3: Click as shown
It may sound like an extra hassle for you.... BUT if Config 1 and 2 are only done to order this would minimize inventory of pouches etc and the holster in any event would be gun specified.
Just some ideas...