If you dont think you will need something 100% then chances are you may not ever use it. It looks to be a reliable little gun for what you described. You do have your basics covered though. From my experiences the .223 is a good little round.

If you think .308 ammo is too expensive consider reloading. I have a friend who reloads and he says he can save up to 80 % of the cost depending on what cal you reload. I will be starting soon.

"Knowledge without experience is just information" - Mark Twain