Given your needs and winter weather daily driving, I would opt for a selectable over a mechanical locker, that way it acts like an open diff when not engaged.
A selectable does take a little more to install and run, but a cheap compressor and tank can be set-up if you don't want to pay for an ARB compressor, cheaply enough that you could carry a spare compressor and still be under the cost of an ARB compressor.
Outside of installer error, I have yet to see an air line fail or get ripped out while wheeling.
