There was some more discussion of 308 rifles going on
here that's worth looking at.
A lot depends on what you want to do with the rifle. Different rifle designs are better in certain areas, or acceptable in all areas. Considering what they cost, I would want to try/handle a few to see what fits me.
I'm not a fan of the CETME/PTR-91/G3 design, but that's personal preference, not saying that the rifles suck. Well, Century built CETMEs have a high suck probability, but that's another story. Dirt cheap mags are easy to find, too. I own one.
I like the FAL, fits me well, battle rifle accuracy, reliable. I have read that it's more difficult to accurize, but have no first hand knowledge of that. Mags are a little more expensive than G3, but there are plenty out there.
The M1A is a favorite of mine. Accurate, reliable, fun to shoot. I had a tough time finding a scope setup that I liked, but that's how it fit me - YMMV. I didn't like how high most scope mounts put the scope on the rifle, and couldn't find a cheek pad I was happy with. I've got an MCS chassis on it now which shows promise, but I need another scope to try it out with. More expensive mags, especially preban hicaps.
The AR10 platform might be a good choice if you can't decide what the rifle is going to be for. It shares the easy to modify heritage of the AR, so if you decide after buying a heavy barrel target AR-10 you really wanted a carbine, start swapping parts. I haven't owned one, or shot one - but I do have a CMMG 308 AR lower that uses G3 mags on order. Magazines might be the weakest point, since the AR-10 doesn't have preban hicaps out there.
Have fun looking!