Waterbug,

Here you go this is where I got my pump. Still working fine going on 3rd year now. This pump and system should work great for your size pond.

http://www.aquariumspecialty.com/air-pumps-stones/air-pumps/heavy-duty-linear-air-pumps

The only difference between a rut and a Grave is the depth. So get up get out of that rut and get moving!! Time to work!!