When I had a similar setup I used to use a 2 of the eGo cases that normally come with eGo starter kits. I think I got them at a smoke shop actually but I'm sure they can be found pretty easily online. They are hard zipper cases that have a couple of straps that will fit batteries, tanks, and even 10 (or maybe 15mL) bottles of liquid. They also have net pockets that are pretty tight and keep things from rattling around. I haven't used them in a while but maybe it's time to pull 'em out again instead of the haphazard way that I try to carry everything around with me now. Hope I could be of some help!
edit: I thought the Aspire 1600mah batteries you were talking about were eGo style or at least self contained: you'll definitely want battery condoms or a case like edyle posted if they are naked batteries for safety's sake.