I go to our local speed/race shop. Most all areas of the country have small NACAR tracks, and near these tracks are suppliers. These hometown NASCAR guys buy this stuff all the time. The place I go to is in a Welder's Shop and does race car stuff on the side. You can get just about any length braided line a bike could need off the rack and then pick the fittings you need, just like Home Depot.
One of the things I have learned restoring and riding vintage bikes is to check out everything around you. We had a Hobby World open near us and I just cruised the aisles looking at stuff that you never know what you might need someday. Trouble is, I always forget where I saw it at when the time comes.
