Thanks both of you for the replies.
I guess it was a long shot anyway, to go for nuffield.
I did find a comparison website to help in my search;
https://www.medigo.com/en-gb but I have not been successful yet in finding a place on there. I did, through the website, make contact with a clinic in Kiev (ukraine) by contacting them directly by mail (medigo want a lot of money to just relay your message to them; screw that), they were one of the cheapest on the site and with them being eastern european I thought the chance of them providing me with an orchiectomy wouldn't be as overly stringent as western european clinics are...
...I didn't state for my reasons for this operation, but the choices they gave me were for either prostate cancer (approx 1600euros), or testicular cancer (approx 3000euros). Both prices include pre-op examination. These prices were much more than what they advertised on medigo (inguinal orchiectomy), but this could just be due to the more complex nature of the conditions. I'll contact them back, but my hopes of them being willing to do this for my reasons seem slim now. But it's still worth a try I guess. I will update on what they say.