Paddy, you can undergo your forklift license test driving a reach truck or a counter-balance. When Joseph was talking about an Order Picking forklift he was talking about an entirely different machine to a reach truck.
Forklift Licenses are National Certifications and there is nothing in the National Forklift Assessment that says you must undergo the test on a reach truck or counter-balance.
Most Assessors prefer to train and asserss on counter-balances but it is not a legal requirement.