Re: co2 tanks, chuffers, and long travel slip yokes
I'm not sure if the John Deere idea would work or not...they're pretty heavy duty, but getting it balanced would be a PITA. Of course, they do have nice u-joints on the ends, and you could easily adapt one to that service. To find one cheap, start looking for farm salvage yards (there are a few on the internet, I think) and tell them the length you need, and they will check for you. You'll need the absolute minimum compressed length, and probably the maximum length as well... Should be much cheaper than buying new.
I've never heard of that "Chuffer" idea. I wonder what happens to the fuel that you pump into the tire. I can't figure out exactly how it would work on a 4 stroke engine. It seems as though the engine wouldn't work correctly. Say you've got 20 psi in the tire, and it's plumbed to the spark plug hole...when the intake valve opens and the piston drops, I think it would suck air out of the tire full of 20 psi, instead of sucking air out of the intake valve which is at less than 1 psi. It seems like it would never be able to fill the tire. I would think that you'd have to have a 1 way valve of some sort on the spark plug hole...but when the piston is on the 3rd stroke (where the gas would normally combust---piston going down and both intake/output valves shut) I think bad things could happen...that engine would be making a lot of vacuum with no air coming in and the piston dropping. I would think that, in order for this to work, you'd have to hook up to the exhaust manifold somehow, instead of the spark plug hole...but you'd have to hook to a cylinder that was "dead" (i.e. no spark, no combustion) or you'd burn up hose/tire/etc. And that connection would have to be directly to one exhaust port...I guess if you hooked to the manifold, you'd just vent the tire out the exhaust. Sounds like a no go on the chuffer, eh?
Not sure about the CO2. The only way to prevent the regulator from freezing would be to warm up the liquid before it is regulated, right? And to do that, whatever was doing the warming would be exposed to the _____(2000???)psi that the tank is holding. Sounds pretty hairy. If you're going to run that many psi, I'd think you'd want to just invest in a very good regulator and attach it directly to the tank. If you're committed to the CO2, then the quality regulator would be the way to go. If you're not, than onboard air is hard to beat. Without anything in your profile, I can't say how hard it would be to rig up an AC compressor, but whatever you have, an electric compressor is easy (albeit slow).
Can't handle spending time under a non-running jeep? That's HERESY!!! You could be drawn and quartered by 4 fully functional, fully locked Jeeps. Best not tell anyone about your TEMPORARY paralysis.
Evolution of tools: stone, hammer, wrench, socket, impact, really big hammer, blue wrench.