The IF#1 is designed to "get you going" and exercise the squeezing muslces in your intestines, and since you don't need to "get going", then you probably don't need it at all.
When I first started the IF#2, I thought that maybe I should take a capsule of IF#1 just to make sure I didn't get clogged up by the fiber in the IF#2...the next day I had ELEVEN bowel movements!
The IF#3 is a milder version of the IF#1; I've never tried it (but it's supposed to great).
From what you posted, it sounds to me like you'll only need the IF#2; as long as you keep yourself fully hydrated (and follow the instructions to take an ADDITIONAL 8-12 ounces of water with every dose of IF#2), then you should do great!