http://www.sewingmachineworldonline.co.uk/Based in Kings Lynn Sewing Machine Steve was a old TSF memberI recently bought a from them after reading about them on TSF... Excellent customer service
I'm in the process of buying an overlocker through them, and the experience has been great!
I can recommend CCB in Rochester High Street, dealer for Bernina, Pfaff, Husqvarna, and Brother machines and also sells pre-loved machines. They also sell a smallish selection of fabrics and habby, and run various courses during the year.