bigsport - you can use normal servos for a 72" ship but you better have metal gears and about 5kg torque min to be on the safe side, an 8 kg torque servo is much better.

http://www.extremeflightrc.com/ - Yaks are great
http://www.pacaeromodel.com/ - see the Laser 200 72"
http://www.sigmfg.com/ - the SU31 is nice