You can purchase CND products from Sweet Squared Ltd. The exclusive UK distributors for the CND products. There is a big clearance sale going on at the moment. Check out the Sweet Squared - Home site and contact them if you want to know where and when. You are correct that you can buy all CND products but the professional ones (L&P and Brisa Gels) whether or not you have had CND training.
I have just checked and you can only purchase sale items from the shop, cash only. There isn't anything available at the moment for us to purchase creative products on-line although I dont think it will be too long.