1. Are you wearing a full fursuit or a partial fursuit?
2. You say you might be getting this pump next year. Do you know how big it is? Is it light or heavy?
If you're wearing a full fursuit, I would strongly recommend NOT putting the pump inside the suit in any sort of pocket or other area. Full fursuits can be extremely hot. For example, if the weather temperature outside is 80 degrees, it can be 90-100 inside the suit. All the heat inside the suit might have an adverse effect on the pump/electrics (and/or medication being pumped into you) and may make it malfunction and stop working.
I think it would be highly preferable for you to wear one of those fanny type waist packs that you can wear on the outside of your suit. Any way to carry the pump on the outside of your suit is much more preferable than on the inside.
And even if you did have the pump inside the suit and it had a malfunction or you needed to get to it quick, then you have to consider the time and effort needed to get access to the inside of your suit to get to the pump. You'd have to take off your handpaws, take off your head (to see), then unzip your bodysuit, just to be able to get to the pump on the inside.
But by having the pump (and/or other stuff) on the outside of your suit, access is easier as all you have to do is take off your head and handpaws. You wouldn't have to worry about unzipping the bodysuit (unless there's some other reason you need to).
Only other issue I can see with having the pump on the outside of the suit is making sure it is well protected/packed so that it doesn't get damaged or something else happens to it.
I'm not really sure what else to say as I'm not familiar with your condition nor have I met any fursuiters in the past or present that have come close to having a condition like yours. It might also be a good idea to talk to your doctor and see what he/she has to say as well. And if you're afraid of talking to your doctor about anything "furry", just tell him/her you're using the fursuit for other activities like parades, festivals, parties, etc.