What is best to use for the streamer itself?
Jimbo gives good advice on this: HatTrick streamers are really good! The page with the contact info is:
http://www.rccombat.com/sections/man...c_hattrick.htm
Length of lead line and length of streamer? Also what is the width of the streamer?
As Jimbo stated, the NSCC rules use 20' of string and 20' of streamer. RCCA rules 5' string (minimum) and 30' of streamer. The New England Gremlin rules use 20' of string and 20' 2" wide streamer (party streamer from anywhere).
One other thing, what is the best way to attach the line to the streamer without having it tear loose?
If you're pre-rolling the streamers to the length you'll be using, hold them rolled with small tabs of masking tape. The masking tape can then be used by the pilots to knot the string around for a solid hold.
HTH,
D