I've done a little searching, and come up with a few ideas. I wasn't able to find any military ones, however, I did come across a few good options.
Option 1 -
I found this on an Indian electrical/battery site. The only issue is, I'm not sure if they sell off that site, much less ship to the USA. I like it because it's flat and I could theoretically velcro it to one of the batteries, and just get two shorter cables that can be put on to the posts. It's fairly simple and would work nice. Not sure if I can get ahold of this one though.
Option 2 -
I found this on Harbor Freight. I could purchase this, and purchase a small project box from radio shack. The switch could be installed in the top of the project box, then I could drill two holes on each side, with a couple rubber grommets, and feed the cables through to close/open the circuit. The added bonus here is that none of the connections are exposed and it would be a fairly clean, nice option.
Option 3 -
I see these on a lot of classics. The design is not bad, but I think I tend to like the one with the "key" more. Maybe that's just me being paranoid that someone is going to steal the jeep (although then again I'm sure if they really want to, they will) but I guess it's not a bad option either. Simple to install, only about $3.96 at Menards, and I won't have to buy new cables.
I think I like option 2 the most, but if anyone has anything to add, feel free. Maybe I'm making too big a deal out of this! Just goes to show how much I love my vehicles!