I do something similar but with a molle chest panel - the Ribz was sold out when I needed one. I use a Condor modular chest panel (yes I know most hate condor but I don't need super high quality nylon for this application) with an attached pouch where I velcro a holster in place. There is also an integrated map pocket if you wanted it to be super low profile and your pistol was small enough to fit. I really like how I can ride this super low (bottom of panel hits waist area instead of a HPG which rides on sternum. The hip belt keeps it from flopping around and I can adjust the shoulder straps loose enough where it is not tight against my body (but still stable) so that I can get air flow. Basically I have it set up so the top of the setup tilts away from body about an inch with the bottom snug around my waist. Another benefit is that the draw is much easier from the lower position than from a high HPG position. It works well enough for me at the moment. If I didn't do this, I would go fanny pack.