I've got a AR10A4 with S/S barrel and with optics it will shoot 1/2 moa all day long at 100 yds..Mags are pricey but if you can find cheap G.I. or Chinese m1a mags you can get them converted for 5 for $100 from Armalite.
If you want a 308 battle rifle your choices are pretty much HK91(or CETME),FAL,M1A or AR10.Some people might argue about the current AR10 as a "Battle Rifle".
This could be a hard decision.You could build 2 FAL's for $1000,mags are very cheap now.You won't have the accuracy of a AR10 though.The M1A is VERY accurate but you don't have the cool factor.The HK will set you back $2000 +or-,EXTREMELY reliable but not as accurate as a AR10 or M1A.
It's 12 of one,a dozen of another decision.You won't go wrong with a AR10.I would go with a AR10A4 flattop.The reason is personally when I have optics on a weapon I want a clear field of view throgh my optics.To me it's distracting to see a front sight at all.Once again this is personally.
For this price you're probably looking at a Eagle Arms AR10.Nothing at all wrong with them but for future value you'r better off going with the Armalite line of products.