You need something more that just a cigarette lighter -- but otherwise, you conect into your house bank. If you're abandoning ship, you won't have to worry about recharging :^))).

Seriously, you can get a pretty good inflator for less that $100 or so. Ours stayed in the sail locker with the dingy. That's forward with the windass motor, chain, extra lines, spinaker, storm jib & trisail (if we carry them), etc. We just tapped into the connections to the windlass with oversize alligator clips.

You can rig something aft, it thats better for you.

As for the tanks, you can obviously do it. However, you'd want a duals setting for the air floor (if you have one), vs. the inflatable. Plus you really should keep the regulator in an envirnmentally stable area.

In my opinion, by the time you're done, you'd be a lot better off with a 12V inflator.

Either way, in an emergency, you'll be digging around in a bunch of lockers for your stuff. If it's a slow progression that you're dealing with, it's one thing. If it's an "Oh shit!. Get on the bus, Gus" sinking -- then I think a proper raft, stored on the coach roof and ready to go is better. Then you just need to grab the EPRIB, ditch bag, and rest of your crew and get on with the "adventure" ;^))))