Matt,
You say that it's a VRV system running on R410a?

I wouldn't worry too much about the R410a training, in the first instant get training on the VRV system.
Contact the manufacturer (or their UK distributor) they will have kit specific training and this will be more useful for you than any training course on the gas.

If you still are looking for courses on the new gases, then there are various centres that offers it, Ellis and Business Edge are two that springs to mind.