RE: which % fuel in hyper 7?
It doesn't matter what you use just stay between 20%-25% you should be fine,as for which brand,try what your LHS has and see which one works best for you.
That's what i did,and even though i found posts which said "stay away from Model Technics",i did at first,i tried 3 different fuels,but when i tried this one(Mod.Tec.),it was great for me and the conditions here at my country!