Snowball back behind the dumpster might be able to get you some drugs.
Bahahaha just kidding, stay away from Snowball; drugs will melt your brain.
That is a totally epic suit, both the Spartan AND the medic. I'm a little bit jealous, not gonna lie.
As for the actual files or dimensions of the medic pack, I can't help you. I *think* I saw a file some time ago, but I couldn't tell you where. If you come up with a stretched octagon shape roughly, I dunno, 8x12 (why not? ) or so, that should do for a pinch.