I like Ruhlman but his Charcuterie book is actually pretty off on a lot of things so be careful, most of the sausage recipes are good, many lack in flavor but this is a good place for a beginner to start. Anyone serious about smoking and sausage really needs to pick up Marianski's book Home Production of Quality Meats and Sausages, this is hands down one of the best books out there.
I have found that the SI do not allow for optimal airflow when smoking sausages, I have not used the jerky drier, and have yet to buy one since I have put a lot of money in my #3, but I would suspect that this would give a much more optimal airflow for properly smoking sausages.
I have done a few hotlink recipes and they have struggled in the SI but are successful by other modes of smoking, maybe I should just get the dryer, or make my own.
Speaking of making your own, I have found there is no need to purchase the sausage rack/bar as you can easily pick up something at the hardware store that works just as good for half the price. I have been using untreated wood/dowels for smoking for about a year now, pretty cheap. I would like to see more smoked sausage on here, including from me
I just need to work out the airflow issue.
Cheers!