I have done alot of shooting with peeps on Uncle Sams M16. I have never shot or mounted an AR of any kind with a scope. I always shot nose to charging handle and did just fine with the peeps and the beat up m16. I now have a 308b coming and need to figure out the mounting issue. Most pictures I see that have the scope at or behind the charge handle have a magpul stock or some sort of cheek piece. The model I am getting has an A2 stock.
what rail extension should I get? Or should I get a magpul stock or a laced cheek bag or something else to help me get onto the scope quicker. My hunting grounds are pretty thick. Most of the time shots only present themselves for a few seconds. Unless I get lazy and sit on the power lines.  

Any ideas?

Thanks,

AL