I'm not sure if there's is such a thing as a skimmer that will not overflow. I read an article,
http://www.advancedaquarist.com/2010/1/aafeature, that has some interesting things to say about skimmer performance. If your current skimmer skims, and you are happy with how quiet it is, you can try to narrow down what caused the overflow so you can adjust/temporarily turn off your skimmer.