Actually, instead of just powered armor, I'd really like some powered utility armor. Perhaps have custom upgrades you can combine with the pieces. Something similar to, but vastly less powerful than, MPS.
Things like Step Assist can go on the boots that already negate fall damage, make some kind of electric armor pants with dash boost, and hook up the ability for both an oxygen tank and an armored jet pack on the back so you can keep your rebreather on. Or just have an upgrade in the rebreather to store additional compressed oxygen tanks.