A lot of the choice comes from the amount of space you have inside of a plane and how strong of servos you need. If you have the space and can stand the extra weight go with standard size, if not use micros. Just make sure that if you use micro servos that they meet your torque requirements.

I have had 2 10 sized Lanier Shrikes and I used standard servos in both of them.

Hope this helps

Ken