Well I use a .220swift which falls (calibre size) in between the 2 cartridges and I destroy Yotes out to 500 yards with it. The .243 will buck the wind much better than the .223. Both are sufficient for the animal but when you start looking at longer distance the .243 will have to get the nod between the 2.
While I do like the AR platform I really have no use for one. There are states that do not allow semi, such as Pa, and hell some don't even allow rifle period! So I use bolt or single shots which are a bit more accurate on average anyway. Granted you don't have the really fast followup shot with a bolt, but with practice you can be pretty dern quick. As quick as you really NEED to be anyway. As far as home defense, thats what I have many pistols and a few shotguns for. Never really saw the need for an AR based platform for home defense. That AR is not going to acquire target as fast as my .45acp,9mm,.40,.500S&W,.44mag, and Up close and personal, I don't think it will do the damage my 12 gauge with 00buck loaded into it will do. Not to mention collateral damage from passthrough or misses with that AR.
Choose the weapon that you are most comfortable with as well as proficient. Also light weight because when you yote hunt you do typically move and hike around a lot between sets.