Just FYI,

You can use ANY servos you want with any rx you want. Just make sure they line-up correctly. Ken will be along soon with a very descriptive graphic which alliterates this very well. (Don't let me down, Ken).

For a trainer, use the most basic standard servo you can get. Don't pay much more than $15 each for them...and you can get servos that will work for less than $10.

Enjoy!!