Depends on what you want to do. For offending liberals, anything you mentioned will do fine. I'd lean toward something with lots of milsurp parts available, like an M-1A or FN/FAL. I'd also get 20-30 NEW magazines and several each of the parts that break the most often. None of that stuff is going to get any more available than it is right now, so stock up.
For pretty much everything else, I'd get a stainless/synthetic bolt gun like a Kimber Montana or a Ruger Hawkeye. The 308 is plenty for most North American game, but you'll want it to weigh around 7-8 lbs. A 10- to 15-lb. battle rifle is heavier, more awkward and more complex than necessary. I'd set up this rifle with a pair of 4x Leupolds in QD rings that return to zero, and zero them both so I'd have a spare.
Whatever you get, stock up on ammo. A gas gun will probably run better on mil-spec ammo, but there is some real trash on the market and it's easy to end up with a case of something that only shoots 4 MOA in your rifle on a good day. Try USGI (if you can find it), South African milsurp, Hirtenberger, Israeli and whatever else you think wise. Shoot 5-10 groups with each type so you know what you really have on your hands. Also, be aware that some people still sell 308 ammo loaded with corrosive primers. Life is too short for that headache.
Milsurp may not be the best choice for a high-quality bolt gun. A few years ago, I bought a nice 308 thinking I'd practice with milsurp, but the best of five or six varieties I tried (including what's listed above) shot about 4 MOA and some of it wouldn't even chamber. I ended up buying 1,000 rounds of PMC FMJ ammo. It shot about 1.5 MOA, which was fine for practice and plinking. I use handloads or commercial soft-points for hunting. Sometimes the big-box stores stock too much of it, then have to sell it cheaply after hunting season ends.
Their loss, my gain.
Okie John