One thing I think may be important to consider is if the class is built around the AR and AK platforms, do you want to use a carbine that has a vastly different manual of arms? How much of the training will be lost by having to translate each lesson to your weapon system? Is your choice of weapon system going to slow the pace of the class down by causing the instructor to have to spend valuable time having to essentially instruct you separately. Does the instructor of the class have enough knowledge of your weapon system to effectively translate the lessons from the primary platforms to yours?
With the investment in class cost, ammo, gear, etc. I am not sure a carbine class is the proper place to be unique. If you want to use a weapon system other than the one(s) the class the built around then private instruction may be more effective.
I could be totally off base, but those are the questions that come to my mind.