I recommend something like the Azoo 2500 or better. I use a 5500 on my Oscars tank.
I also think anyone should stay away from this style Tetra Whisper air pump. This pumps design is BAD, it will not last long at all.
Azoo + 8ft of line + bubbler stone/wand = $15-$35 depending on the size of the pump. This is a rough estimate from foster and smith, not including shipping, on a 2500 up to a 9500(which is like for 100+ gallons).
Oh, you can also add a check valve to the pump. Pump insurance at $1-3 for a 1-2 pack.