Hi Kat
First off, try not to panic. There are LOTS of great high volume surgeons throughout the UK. Here is a list of some of them...
https://prostatematters.co.uk/prostate-cancer/where-to-access-robotic-prostatectomy/
With a radical prostatectomy, there will be many surgeons who will be up to the job. I know it's hard not to look for THE top dog in the field, but the fact is, there are many experienced surgeons out there.
I guess factors that might be worth considering are geographic location, how far are you willing to travel, after care and ongoing monitoring, where the tumour is and what the staging is, your budget...
Considering all these factors, you should be able to find a great surgeon to meet your needs.
I know I felt exactly the same when my husband was diagnosed and panicked about finding the best surgeon to do the op as quickly as possible. But after doing a lot of research we made a decision (my OH had RARP in the North West on the NHS) and had the operation 10 days ago.
It's a very difficult decision to make and you have my complete empathy. If you need further help, feel free to DM me, although I think you may need to post on the board 10 times before you can reply to messages.