As far as the materials go, try Ideal Steel in Smithtown. They are on Southern blvd. near the Smithtown Nissan dealer. I attempted building a top for my 125 over the summer out of square tubing based on an idea I saw on a 90 gallon at SCF&R. 12 feet of 3/4" square tubing was under 15 bucks. Had I built it a year prior to this past summer, I could have built it for nothing at Carls welding and I would have had the tools to build it perfectly as well.