RE: GY240 or GY401 for my Caliber 30
I started out with a GY401 and bought a cheap futaba digi servo. It wasn't holding my tail very well and I then bought a S9254 separately for it. It made a HUGE difference and my gyro was really easy to set up with it. The slower servos aren't meant to be used with gyros so if I was you I would do what Barricuda says and buy one from the start. You're basically saving money spending more now then having to buy a new servo later on.
Ross