all good answers!
you really could use the shotgun for more hunting than you can use the bow. waterfowl, upland, big game, etc.
so the one gun does it all is the 870, get one.
AND keep your eye open for a good used bow, because for deer hunting you cn get away with the bow for everything, archery, rifle (no reason you can't use it in rifle season) and muzzle season too.
also, in most cases you cn practice in your yard or neighborhood.
so, get the 870 and then get bow..