Its actually pretty simple to get to work, though finding a pump that will work a vacuum first is a little difficult but not very expensive. I would suggest looking in your local Aquarium supplies store. Many of the newer dive systems use a simple impeller pump and a middle chamber, also if you are not worried about acutally seeing how it is working then check if domestic water pipes are small/big enough to fit.

Accesories to allow propeller and servo transmission to pass the end caps of your tube are easily (if not expensively) available.

There are plenty of sites describing how people have done this, spend 30 minutes having a search...you will learn a lot more than can be typed here in a few minutes!

HTH

Andrew.