So, on a model 1, without an external controller (the Auber) 250degrees will be your cap for high end of temp. To get crispy skin, you really need to be higher. The low and slow method will pretty much always yield rubbery skin on Chicken and Sausage and whatnot. With an Auber, you can push the temps up to the 300-325 range on other models... I'm not 100% familiar with the capability of the heating element in the #1, but hopefully, someone else will chime in who is.
My way for doing chicken and other things where I'm trying to avoid rubbery skin is to do a split cook. Basically, smoke the meat up to 70-80% of desired finished temperature, then finish on the grill. This is normally the way I do wings, and the way I've done spatchcocked chickens. For wings, I smoke for about a half hour (That's a half hour of smoke production) for whole chickens or chicken quarters/halves I'll smoke for 45min to an hour. Then, finish on the grill.