This website makes it easy to do it all yourself. They have so many different options available, and insure that each part of your order that you need to fill in is covered. I called to ask their advice about which type of shade would be best for what I want, and found they have good, helpful customer phone service. After I placed my order I saw where they advise you to add 1/8th inch to the width you get. I'm glad I didn't do that, because I wanted a fairly tight fit for maximum insulation value. I measured my width precisely and ordered it that way, and it came with an 1/8th clearance already built in, which was perfect.