I know there is a long established gun dog society in Usk, they run working tests and trials so I suspect they will also having training classes just as Shrops Gun Dog Society do over the summer.
Other places to look are on the gun dog training website. Also KC website has a list of accredited trainers for each area. If I knew 12 months ago what I know now....I'd have taken Coral to the KC puppy training to get the basics in before starting gun dog training.
Kevin Powell is in Ludlow which maybe too far north for you? I am aware of a trainer in he Gower area which I suspect will be too far south?
Alternatively, you could ask he breeder if they are local for recommendations?