I don't have that airframe. But I have several 3D planes about the same size. I like the Futaba 3305s for an inexpensive strong servo. On 6v they make 130oz( 8.9 KG-CM) of torque, have metal gears and only cost $35 US.
Here is a link
http://www3.towerhobbies.com/cgi-bin...&I=LXDWF8&P=ML
David