I would just make sure it has no artificial ingredients or additives (absorbic acid is ok). Juicy Juice is from concentrate, so the flavor might not be as good as using not-from-concentrate juice but would still work.
has some good info about different yeasts. General rule of thumb, since you mentioned champagne yeast, is that it will tend to ferment much drier (higher alcohol % and less sweet) than other yeasts. With that said, I will be making a cider w/pasteur champagne yeast as soon as my fermenter is free and backsweetening it to taste to try it out.