Would one of NAR's Patrol officer IFAKs be too big?
http://www.narescue.com/Individual_P...C=3000250D2301

There is a little belt/PALS holder for it as well:
http://www.narescue.com/IPOK_Holder-...C=3000250D2301

ITS also has a few vacuum packed kits that can go in a pocket and are pretty small. I am trying to remember who they actually get these from but they are decent and small enough to not be a giant pain in the rear.

http://www.itstactical.com/store/its-edc-trauma-kit/