Does anyone know a shop where piano/keyboard music can be purchased please?

No. but there are a number of good websites where you can, for a small fee, download more or less anything you want. Type in the song or piece that you are after followed by 'sheet music', on google and the links should come up. Hope that helps

Thanks matmat - it would be really good to browse in a shop but I will resort to the web. Many thanks for your reply.