RE: QQ E-Yak
HS-55's, E-Flite-75's, etc are just fine. Futaba 3114's have nice torque... The Berg 4 channel Microstamp and 7 channel are nice clean, light receivers (Castle Creations manufactures then now)
I suggest ThunderPower 900-1320 lipos... lightest of the bunch and balancing taps.
$54 for 4 servos
$55 for a battery
$37 for the Microstamp w/ crystal...
Can't see how you can get it under $100 unless you go too cheap to enjoy the airplane.