This is a question that has dogged competition cooks for years, with some of them carefully removing the skin from chicken thighs, rendering the fat, and then refitting it to the thighs to finish cooking. A whole chicken that is smoked at temperatures in the 225 to 250 range will necessarily have the dreaded rubbery skin. That's why I prefer to smoke my chicken over low temps for an hour or so, and then finish it at a higher temp (350) to finish cooking and to crisp the skin.
Just put some babybacks on the smoker with a slather of yellow mustard, soy sauce, Worcestershire, and a dash of bourbon. The mustard slather helps keep the ribs moist and makes a good "ground" for the spice rub.