Hi Tx! You've come to the right place to learn all you possibly can about these SI smokers! We have several sausage experts on hand here, and I'm sure you'll be hearing from them!
The Auber is a fantastic addition, if you desire really tight temps. I also highly recommend the permanent-mount probe (wall mount). It takes all the variables out that can be introduced by probe placement, and brings a level of consistency to the Auber that the removable probe can't. It's an easy installation, and there is a detailed instruction post under the Auber section.
I use the James dryer for jerky, but have never made sausage. It draws air up through the smoker. If you really need to have smoke rolling the entire smoke (not sure why, though), you could wrap the chunks or chips in foil to minimize the effect of the added airflow. Just a thought. Pork Belly and NDKoze are a couple of the resident sausage experts, though.
Don't be shy about any questions concerning pros/cons of these smokers; you'll get honest answers here!