So, you have an airstone skimmer? Meaning, there is a little wooden airstone connected to an airpump, and another small water pump, or does the action of the airpump draw water into the skimmer. I've never seen an airstone in sump skimmer; typically they hang on the side of the tank. If it's an airstone skimmer, you should be able to raise the whole skimmer up so that it sits in less water. If you have an adjustable airpump, chances are it's a tetra luft; is this right? I've also never experienced an airpump that's "too powerful" for a skimmer; almost always it's the reverse. Are you sure this skimmer is run by an airpump? Or is it a water pump with a venturi, meaning you adjust a knob to let air into the water stream. Maybe you could post a picture.

As far as recommending an in sump skimmer, I'd need information about your system; how big is it, what kind of livestock do you have, and what is your budget for this?