I think there is a heli school at Southend Airport, so perhaps a visit to them to get a few answers over credits and the like.
Perhaps a trial lesson with them, to get a feel for it in a suitable environment? It will count as time should you decide to go for it.
Once you have some facts, you can then look round for a flight school which suits you.
Usual caveats that any school may say 'you are a natural' for business etc. Plenty of threads here over such things.
Also a PM sent.