Holy crap avid juicy 3's might be the worst brakes ever made!!!! I have elixir CRs.
What size frame are you? I have another set of elixirs I could sell you. I put them on my wifes bike but took them off when I sold it.
Edit: frame size wont matter.... since you have a FS bike the routing will be different so you'd need a new hose for the rear brakes. Do you have a bleed kit? Its easy enough to do.