There are several fishing vests available with inflatable bladders so they can double as life jackets. The vests have enough pockets to comforably carry a good deal of gear. I have one that I wear when I go fishing on other people's boats. I know they always have plenty of fishing gear, but, the safety gear is sometimes lacking.

I don't have a detailed list, but, in my vest I easily hold things like a VHF handheld radio, strobe, pencil flares, mirror, whistle, dye marker, cyalume, some line, a knife, a modified version of Doug's pocket survival kit, and a millenium bar or two. If I go overboard, well, I have a fighting chance.

I know your concept was to marry a self inflation device with another kit. I've just found that the vest itself is a nice container. It's like a pilots overwater survival vest.