The choice is a personal one and only you can decide what to buy. As far as Florida is concerned, it is legal to use an AR for hunting. The only requirement is that the magazine can only hold five rounds. I have a 10 round magazine that I inserted a block of wood under the follower to limit capacity to five rounds. You said that you would like to be able to find affordable ammo for the gun you buy, have you considered an AR-15? You can buy a new Smith and Wesson M&P 15 for $599, which will leave you enough left over to buy a shotgun. There are several quality bullets that make the .223 a perfectly good deer and hog caliber. You'll be hard pressed to find cheaper ammo or reloading components than the .223/5.56mm.

It is also legal in Florida to carry a sidearm while hunting. If you have a concealed carry permit you can carry concealed, if not you are still allowed to open carry while either hunting or fishing. It would be wrong to keep you from carrying a backup sidearm, there are too many critters that can hurt or kill you down here.