Thumbs up, all the way. Being in good shape is more important in a difficult situation that any gear you might carry.

Lack of money or time to go to a gym is no excuse. You can become extremely fit without any equipment whatsoever, just your bodyweight and strict discipline. You can also easily improvise all kinds of effective fitness equipment, like sandbags instead of free weights, climbing rope, pullup bar etc. It doesn't have to be expensive. I just got back from the basement where I did 6 rounds on my heavy bag that I made out of a $2 navy surplus duffle bag. It works just as well as the commercial stuff.

Woodsloafer, those are all excellent recommendations. I would also add the Navy SEAL Physical Fitness Guide to your reading list. Another excellent resource is the site by the boxing coach Ross Enamait:
http://www.rosstraining.com/
Ross is the real deal. Lots of great ideas for bodyweight conditioning, strength training, sandbag lifting etc.