Choosing a pond pump

Question:
How do you pick a garden pond water pump?
I bought a house that has a three-tiered water fall pond in the backyard. The pump that was previously in there died and now I have to buy another one. My question is, how do I know which pump to purchase?

The pump would need to pump the water about 20 feet horizontally and 5 feet vertically. Other than that, I don't know what other information would be needed to answer this question.

I'm looking for a low-cost solution pump if its possible. To replace the exact pump that was in there would cost nearly $600.

Thanks for any help any of you can offer!
The one like you had would be the best one. A good pump for you would have a head of 10' at least and be able to be attached to a manifold to spread out the water.
Oase makes a good pump. So does Little Giant. Check them out and look for a pump that pumps at least 5000 gph.
Remember that the more expensive the pump usually is the least expensive to operate and therefore is the best buy.