What's your budget like. This is a neat product that has been posted in other places on the site, for a compact transportable system.
http://www.aspectsolar.com/solar-power-pack.html This unit is ideally designed for charging phones, laptop or camera batteries, etc. The price isn't a deal killer. You don't want to keep this kind of battery in the direct sun though, they can have a meltdown, same for cell phones and the like.
http://www.expeditionportal.com/forum/threads/126002-Exploding-GPS
For close to the same money you might be to able add a solar charger to the vehicle, and then add accessory sockets for charging stuff. Whenever possible of course, you want the 12v version of battery chargers for your devices. Bearing in mind, the vehicle battery is small, and you are basing your main operations at the vehicle, it might be a nice option. Particularly when you might also add a fridge, 2 way radio or something else down the road.
If you're really hooked on the idea of the compressor thing, then go for the best unit you can get and the best battery. Bear in mind, if you've used up the battery charging laptops and batteries, then the compressor and jumper won't do you much good. I like the idea of being able to replenish the batteries. That being said, a 100 watt panel is going to get you about 5amps or so in ideal conditions, the unit listed above, probably half of that or less.
