The long-established IR schools such as Bond, Bristow and Helicopter Services have a waiting list of over a year.
http://www.caa.co.uk/docs/33/Doc%2031%20v89.pdf
There is no protection as such if you pay in advance although there may be some if you pay by credit card in instalments.
Search on the Rotorheads forum for more info on the schools.
Cheers
Whirls