I can’t help with any current puppies but we went through the Cavalier club to find ours.
http://www.thecavalierclub.co.uk/start.html
Our breeder was seriously dog crazy- but we met our dog’s mom, maternal grandmother and grandfather and he is the loveliest dog- fully tested prior pick up and regular clean bill of health from the vet.
Good luck- they are sweet little guys!

Hello,

We are looking to get a cavalier King Charles spaniel.

Could anyone let me know if there is one for sale or recommend any good breeder?

Many thanks.

Eleo