Gerber (I think) does have a very nice little camping axe that comes with a knife stored in the hilt.
I would also look into getting a good camp shovel - if you get one that takes an edge it can do all the rough work that might otherwise fall to your
knife. That keeps your knife sharper, longer. A good sharp shovel can almost
take the place of an axe or machete should you need one.
Also, anyone who has had to dig a large-ish hole with a small-ish fixed blade knife can attest to the value of the humble shovel. :shk:
So, given the choice I would have a 4-5 inch sturdy fixed blade knife, preferably with a couple inches of serration on the back end for cutting lines
and saplings, as well as a camp axe, a camp shovel, and depending on the situation, (urban vs. rural vs. wilderness) a sturdy multi-tool and/or a
Multi-tools are nifty if you see yourself having to work on anything mechanical, like a generator, radio, or even a car, but they become infitely less
useful if you're in the wilderness. The exception to that rule is if you're pretty handy with traps, and you brought some snare wire along. Most
good fixed blade survival knives will have a little notch for cutting thin wire, but I find the pliers to be very handy. My main gripe with
multi-tools is that it's sometimes hard to find and pull out the tool you need under normal conditions, nevermind in the dark, drenched by freezing
rain, with one or more injuries. I consider them a fair-weather friend, in other words.
It also depends on how much weight you're looking to carry. Less = Better, obviously, so if you don't need an axe and a shovel, don't bring them
'just in case.' A single good knife can do all that in emergencies. If your goal is to get somewhere fast, and remain highly mobile,
I like Gerber's multi-tools - the one I still have has survived a lot of normal wear and tear, not to mention some abnormal abuse, and it's stood up
well, works like new in fact.
I carry it with me often, and in an emergency I would almost certainly take it along. It takes the place of a small folder on the hip, and does a lot
more (3 Blades > 1 Blade). A camp axe on the other hip (I don't carry a sidearm) and a shovel and a skinner in the pack, and I'm a happy camper.