I hope Leonard won't mind too much, but from my BOM: 125ft. 5/8x0.035 and 30ft 1/2"x0.035. There's a bunch more other sizes, but that's the bulk of it. Also, Mike on YouTube (LeagleEagleAirplane) says that 15 ft lengths work out ok to minimize waste, although people here may have other suggestions. Shipping is the major problem, so if you can, buy locally and pick up. I'm in the Seattle area, so there are a number of sources for 4130.