These are the mini servo I use. There is a continous and standard versions.
http://www.robotshop.com/en/9g-conti...cro-servo.html
For mother boards your options are clark22 or 60, asp, IBU2 or 3, or elmod.
space looks to be a premium and i think the clark is the smallest, its quite compact.
Dont know about the asp, but the others support servo drive for gun recoil if its important to you.