I am looking to install a new Scan Anderson 10 into an existing fireplace. I have two 11'' flues and I was wondering which liner I should choose. One dealer is suggesting that I choose Stainless steel forever flex. I like the price better than the Armor Flex option but I do not want to choose a cheap product I will end up regretting. Anybody have any experience with the forever flex product? I will need about 22' of pipe and will connect directly to the top of the stove. I would love to have a cleanout so I don't have to disconnect the pipe every time I need to clean the flue but I am unsure of the options? Also is it necessary to insulate the pipe? The chimney is interior but at least 10 feet does go through an unheated attic. I am not looking to get cheap and will buy what is required but I don't want to waste money either. I figure I will seal the second unused flue at the top and put a plate over the damper area around the new 6'' pipe. Any suggestions would be welcome.