Isn't it easier just to make your own pump box and fit it to a trolley and away you go. Most of you stick your backpack on a trolley anyway, so why not go the full distance.
Electrical box, small 3 amp pump, 7ah battery, pulse width modulator, voltmeter and a on/off switch.
Easy to repair or replace any parts and simply secure onto a trolley of your choosing. Make it as simple or as complicated as you want