Take along a battery powered "sawmill". We used an 18v Milwakee unit. And a coarse metal blade. With one charge we were able to remove all four lower legs (nothing but hooves and bones anyhow), remove the head, saw the cow in half at the last rib, and then slice the whole critter from neck to butt right down the spine. It had to be quartered to load it on the float plane anyhow.... The sawmill makes all of this relatively painless.
A small set of pulleys and some rope are highly advised. There are times you need to pull that moose 20 feet to get it out of a hole before setting to field dressing. You can't just grab an antler and drag the thing like you would a whitetail buck...
Moose don't need massive power, despite anything you've read. A .308, .30-06, .270 whatever works well. Don't worry about caliber, but DO select a GOOD bullet. Opt for heavy for caliber (180 in 30s, 160-175 in 7mm, 140 in 6.5mm) and something like a nosler partition (NO Ballistic tips or similar deer bullets). Eastern moose aren't the 2000 lb monsters that Yukon moose are, and even the lowly 170 gr 30-30 will drop them very quickly with proper bullet placement.