shop around
There are a number of training providers in the UK with good packages , have a look at what all of them have to offer and visit the places and try to get a view behind the glossy handouts.
Take a good look at the small print befor you commit yourself and dont put more than a few quid "up front". Try to get a picture of the state of the staff conditions , after all even the best instructor will not be able to give his best if he is being shafted by his employers.
NOTE This advice is of a general nature and should be taken when veiwing all training outfits.