Randy
I faced a similar situation. I took the approach you can smoker less in a bigger smoker but you can't smoke more in a smaller smoker. I have the number #3 and have not smoked more than one butt and 3 ribs at a time. i have no regrets. This smoker is awesome. If you can swing the #3 do it. The smokin-it brand is top notch!
BTW, Joe and Tony provide great advice all the time