Tsonda,
While you are welcome to bring a FAL, AK, SiG, Mini 14 or 40 watt directed energy weapon to class, the course is designed around the M4 platform.
All of the TTP's are designed around the M4 platform.
What that means is that while you will shoot and probably have fun, you won't learn a whole lot about working with anything other then the M4 system.
If 19 people have AR's and one has something different, it would not be fair to the rest of the class for me to spend 50% of instructor time to cater to one guy, while everyone else has the same platform.
Your choice of course, but if you want- as you stated- to get more time on the AR, you probably need to do exactly that.
If you want to run 7.62x51, may i suggest Randy Cain, Louie Awerbuck or Pat Goodale- all who run excellent rifle classes.