The Ringmaster is a great plane but the kits tend to have a few issues related to the design being more than 50 years old. Is this the kit with the large leading edge or the sheeted leading edge? Make sure the bellcrank platform is very secure (most folks replace the light ply in the kits with a larger 5 ply piece) as the original design is a bit lightweight for current engines. The Ringmaster will fly with an engine as small as a 19.
As far as the Sullivan fiber lines they are really draggy. They will work but only if you move the leadouts back a couple of inches as they will bow badly behind the plane pulling it inward as you fly. .015 steel lines would be better and can be ordered from Brodak or Sig or check the web for a company called Good-To-Go models (a friend of mine who runs a web based CL specialty shop, Ed is a fountain of good CL info if you have unlimited minutes on your cell phone). Most folks use the sulivan fiber lines to reinforce things like spar splices as they glue well with CA and epoxy.
Regarding tip weight you will need about a half ounce to keep the plane tight on the lines. With tip weight and proper leadout placement you need very little outboard rudder (maybe 1/8") and little engine offset (maybe one washer under the front mounting bolts) to keep the lines tight.
See ya in the circle!
Bob