I run my undertank wet/dry with an AquaClear Model 70 powerhead. It's on a 180 gallon tank with a 7 gallon biochamber and it pumps up to almost 55" with no problem. I cut off the "air inlet" and put a piece of tygon tubing over the resulting hole.
While it doesn't do the huge turnover many people seem to favor, I've checked it's flow rate and it's running about 360gph which turns my tank over 2 times an hour which is plenty of flow for a trickle filter. It's not my only filter though but it is my primary biological filter.