You’ve already been given some good ideas.
To meet your requirement of something you can attach to your existing belt (assume it’ll be threaded thru your belt loops) and your stature, I second the recommendation of a Bladetech kydex holster with their dropped-offset bracket and either the Sting-ray belt attachment or a Tek-lok. You can either thread the belt thru the Sting-ray or clip it on with the Tek-lok. Sting-ray will be more secure, but the Tek-loks are easier to take on and off.
Or bite the bullet and go with the BOSS hanger + kydex holster such as the Bladetech. The BOSS allows you to adjust the height and offset(by using different length spacers). The BOSS hanger is becoming pretty popular even if you opt to shoot a different division. I use the BOSS for 3 different divisions that I shoot (it’d be 4 if I needed a holster for PCC...).
USPSA changed their rules for offset in 2018, although for Prod division it’s only a 1/8” increase, for a total of 2 1/8” as measured from the inside of the belt to the gun. There is an allowance the Range Master can grant due to “anatomical considerations” and the rulebook acknowledges not all competitors will be able to comply. For Limited, L10, and Open you can go up to 3 3/8” offset.
For mag pouches, there are some that use a tek-lok or clip for easy-on/off, but most of those will not have any offset to move it away from your body. The same 2 1/8” rule applies to mags.
As far as belt, the ones that you see most often at USPSA matches are the two-layer belts made by CR Speed or DAA. The inner belt threads thru your belt loops and the outer (more stiff) belt attaches via velcro. Your holster and mag pouches are attached to the outer. I have both, and the DAA is probably stiffer than CR Speed. When ordering, order 4” larger than you current pant size (I wear 34” pants and use a 38” belt).
