It’s a deep dangerous dive into the gear world of uspsa. Welcome! As someone who just jumped in headfirst I’d probably go with the ghost pouches and a double layer belt.
You can get deep into mag extensions as well with all the different base pads plus followers. +6 doesn’t always mean +6 with one in the tube so make sure to test them out.
I do believe a drop offset hanger is something I would get and I wouldn’t care about the holster.
Everyone says run what you have and shoot a few matches and I wish I would’ve done that.