I recently purchased an 8" plate glass blank from the place in Jacksonville (same place??) and was very pleased with the results. Made an f/6, and have esentially finished it, but not coated yet. I had some minor scratching problems in the fine grinding process, but not due to the plate glass - my technique was at fault. I would highly recommend that you go that route, especially for a first try at making a mirror. An 8" or 10" would be a good start, but I would recommend an f/6 to start. Still fairly wide field, decent image scale, especially in the 10", yet easier to figure. I would also recommend getting a book, such as Jean Texerau (sp?),"How to make a Telescope" available fro WB. It's nice to have all the info necessary in one volume, from one publisher, representing a single point of view and perspective. Some of his info is dated, yet usable. ie, pitch lap moulds are a better way to make laps than what is in the books.