Hey there! I don't know how many hanks to use on an FS pony, unfortunately, but I do have all three of those colors, plus another red or two, so I may be able to help you narrow down your choices a bit :heart:
Here's a photo of my Apple Bloom (rehaired with Cherry Pie) along with Sugarberry, Candy Apple, Pomme D'Amour, and Razzle Dazzle:
It's worth noting that Candy Apple is a matte color, so it doesn't shine like the others, and Sugarberry is a really, REALLY bright flourescent pinkish-red. Pomme D'Amour is slightly more orange and slightly lighter than Cherry Pie, which is a somewhat yellow red (as opposed to pink).
I too have been toying with the idea of a Roseluck custom, and if it were me, I would go with Razzle Dazzle (or Rasberry Sorbet) and Venom, as seen on this custom (not mine) here:
Toadstool Treasure Custom by ~psaply on deviantART
Hope that helped! Best of luck with your custom!