This sounds interesting. I was going to do a playthrough of Green with just Jynx, but this seems more fun.
I shall be going through Green version, and am unable to trade between games. Difficulty would be preferable at medium or hard, please. As for when I get the challenges, it doesn't really matter. I'll be holding off from starting until I get at least three challenges, but I'll accept new challenges as I go along so long as they don't conflict with any prior challenges.
I will be accepting any and all challenges that are given regardless of how many I already have so long as they are applicable. Keep 'em coming, I say! I have no restrictions other than trading or forcing me to do massive amounts of grinding before I so much as attempt something. I don't really expect to see it anyway, but no "Party must be at least level X" or "Pokemon must at least have move X" challenges unless it's something it would realistically have by the point in the game the challenge would take place at.