The problem with trying to find the lego pneumatics is that they have been all but discontinued by lego. they replaced them with the new linear actuator in the last few years. If lego education doesn't have what you are looking for you can try peeron and bricklink.
You can look here for general part info:
http://www.peeron.com/
And for purchasing you can try Bricklink:
http://www.bricklink.com/store.asp?p...Brigade&rID=-9
I also use Ebay a lot for buying old lego components.
Hope this helps,
Garret