For mag pouches I like these....
https://www.skdtac.com/ITW-FASTMAG-p/itw.110.htm and the mid or tall Esstac pouches
https://www.skdtac.com/Esstac-5-56-Single-KYWI-Pouch-Midlength-p/ess.545.htm but I'm not sure how the Esstac would do on a belt.
For a belt I'd echo what TWR said about battle belts. I prefer a very stiff nylon belt for everything now. I've had a Volund for a while and love it. No complaints at all.
Dump pouches are a good idea for any class. I keep a notebook and pen and take notes all day to refer back to later. A steno notebook will curve around and allow nearly full use of the pouch. I'd also I'd recommend a size smaller than you think you'll want. A giant bag flopping around behind you isn't fun and the bigger it is the more random stuff you'll cram in it that you don't need. Mine is barely big enough for a Nalgene and I'd prefer something just a hair larger, but not much. I can fit a 16oz water bottle, sharpie, notes, and a mag in it--or no water and several mags.
Everything Mike said. A HPG chest rig is an interesting idea and a good excuse to pick up a piece of gear that you'd use at other times too.