You just posed a very broad question. There likely isn't a best 308 in that range. The key difference in the Remington line are the different stocks you get on different models. Some of the stocks are much stiffer and actually allow the barrel to float free, which is critical for good accuracy. Others claim that they are floating, but they aren't stiff enough to not touch the barrel if you use a bipod.
I would try to handle lots of different Rem700s and see what stocks feel good to you.
What accuracy level are you trying to reach? A custom benchrest gun will shoot .1moa while a factory Rem 700 shoots about .5-1moa. Getting .5moa is pretty easy, getting under .3moa is pretty hard.