I went to school to be a commercial pilot and somehow managed to work my way through my Certified Flight Instructor ratings. As far as your OCS "kit" is concerned, I've heard that having prior flight experience helps a lot and I have also heard that it does not really make a difference at all. It is my opinion that any amount flight time gives you an edge at the board over someone with zero flight time.
Where I believe prior experience as a pilot will really make a difference is after OCS during the academics in API. Most of what you are taught in ground school and required to exercise as a civilian pilot translates well into much of the items taught in API. Having working knowledge of the aerodynamics of an airplane, FAA flight rules and regulations, aviation weather, aircraft systems, etc will be tremendously beneficial. That being said, you don't necessarily need to be a pilot to learn that stuff. All of it can be taught to yourself with the wonderful help of the interwebs. Even the API coursework is online if you look hard enough.
