Speak with Stuart Kilner. He is your closest dealer based in Essex, and will stock all PFT original parts for your G5. If you haven't used a machine before it will be a good idea to drop the machine to him, get it serviced and ready to use, buy any of the accessories you will need and then when you go to collect it have a days official training backed by PFT.
In the long run you will benefit 10 fold by having a local dealer who already knows your machine and equipment and will get you up and running usually with a few phone calls