This is what we have done so far. There is too much to explain so feel free to ask questions. Two-stage vacuum pump to grab balls, two-position pneumatic kicker with surgical tubing assist and air stops. 8 wheel plaction tread drive with four cims on standard tough boxes. 36 foot average long kick distance.
CHECK IT OUT IF FULL HD
http://www.youtube.com/watch?v=X_dnzebFqDk