I stopped in & talked with the guys at Iron Ridge (
www.ironridgeguns.com)a few weeks ago & discussed their .308, along with some other projects. They have a great handle on what they are doing and the parts they are using. Can't wait to see a finished product.
Lewis Machine & Tool (
www.lewismachine.net) has been advertising a new .308 based on their MRP platform. It's here in SHOT for display & just like their other rifles, its indestructable. I've used LMT in USASOC & can personally attest to their durability, accuracy, and reliability (their rifles got me back home!!!) Although pricey, a bit heavier, and may take a 6 mo to a year to get, I will definately have one soon.
Another option is LWRC International (
www.lwrci.com) with their REPR. I have not been able to test one yet however I have nothing but good about LWRC and their products/service. The cost is close to $4K for thesse rifles but I do believe that you get what you pay for with them.
There are other manufacturers out there that make .308 AR's, look around. I would highly suggest avoiding Armalight and DPMS as I have personally seen too many problems with their products. Remeber to consider what you are using this for; if it's for show then look for the best deal. If it's to use and possibly protect life then look for the best, period.