The Aqualifter pumps work very well, I have several that I use for a lot of things, overflows, auto top offs, quite handy little pumps. Putting one on your overflow to evacuate the air works like a champ, just have it dump into the back side towards your sump to keep the air out of the tank and you'll be a lot happier, the powerhead blowing air drove me nuts, anytime it wasn't then it was clogged and I knew an overflow was just waiting to happen.

One note, the AquaLife pumps do require some periodic cleaning or they begin to get clogged with algae and such (every few motnhs or so)... or you can do it the lazy way and just replace the flapper valves when they give up.