Waterfall pumps usually just means that the pump produces more flow
(gph). You have a couple of important choices ahead of you. The
reason I know this is becase until this year I had a 800 gph and a
1200 gph submersible nursery pro pumps running and I wasn't concerned
about pumps. I enlarged my pond and added a 4200 gph external
sequence pump and I did my research.

The big pluses and minuses are really gph at head height and energy
consumption.

You already know the height you need to raise the water, so find a
pump that matches the flow you want at that height. For example, I
have 32 foot of 1 1/2 inch pvc running from my skimmer to my filter
and it rises about 5 ft. My pump is running at about 3000gph becuase
of the height over that distance. -- I now wish I would have bought a
bigger pump... oh well.

Now, for energy consumption... spend the money now on a good energy
conserving pump because it will pay you back quick. There are some
great posting in this news group to help you calculate your $ savings
if you buy a good pump. The waterfall pump I almost bought at a local
store had a consumption of 800 watts instead of the 180 watts mine
uses. The best part, I bought the better pump online for the price I
would have paid for the energy hog at my local store. The is a
great discussion thread called " Pump Advice Please" that may help
you with calculating energy consumption whether its a pump rated on
Amps or Watts.

Hope this helps.