Navigator,
Lots of useful advice here, However I just thought I would stick my nose in for good measure!
He who has the money has the power! What if you find at some stage in your training you are unhappy with the service/quality or you find another school that you prefer......what will you do?
I taught at a school where getting a refund for ANY reason was like trying to get blood out of a stone.
If you wish to limit the liability then 'stage payments' might be best.
It is YOUR money, spend it wisely.
Good luck and enjoy your training.
JWF