I would say that the most popular type of smoked/cured sausage that we see is either German Sausage or Andouille.
Andouille sells more than German (for us), but it is also not completely a smoked/cured sausage. Sometimes it is fresh, sometimes cured/smoked, and sometimes just smoked. It also doesn’t quite fit the generic smoked sausage category in my opinion. For what is strictly seen as a smoked and cured sausage, I’d say our H German Sausage Seasoning is the most popular option.
German sausage would be my final answer!
I’d also throw Polish Sausage into the mix though. Grouping German and Polish sausage together, that makes what I’d say is the most popular set of options for smoked sausage. They are somewhat similar, and together they constitute what I view as a traditional smoked and cured sausage.
For casings, most often, I think you’ll see 32/35 mm Natural Hog Casings. A few people may use Collagen Casings, but natural casings are still the most popular there.
Both natural and collagen casings will absorb smoke color and flavor really well.
For meat type @sausage-king is right. Most traditionally, you’ll see somewhere between 80/20 (beef to pork) to 60/40 ratios. That exact ratio is very much subjective though, and really is just a personal preference. If it was me, I’d make them out of 100% pork just because it is less expensive.
Hopefully that helps. Let us know if we can provide any more info.