The grape juice thing has been debated in great detail. Fructose is a shit carb, and I wouldn't mix my whey with it. Use some dextrose in a whey shake mixed with water, and call it a day.
I might be mistaken, but I think fructose goes through the liver before its release into the bloodstream. That would make the energy boost from fructose kinda delayed. IMHO fructose is better post-workout, but beforehand you want some glucose. Try coolaid