Sausage making is loads of fun. We make several batches a year - uncooked sausage freezes well, and it's nice to have to throw on the smoker when doing other things.
We use our Kitchenaid mixer to do both the grinding and stuffing. If I'm in a hurry I'll call the butcher to have pork butt ground, but generally I like to do it myself so I can control the meat/fat ratio. The kitchenaid isn't super fast, but it doesn't take too long to push through 7 pounds of Italian festival sausage.
As far as casings go, I rarely ever use them any more. I've really like forming the sausage into 1lb "loaves". Wrap then in original Saran Wrap or Aluminum Foil, refrigerate overnight at least (this is an important step - sausage that has rested does really taste better) then toss in the smoker just long enough to let them set up slightly - remove the foil/wrap and then smoke until done. Some recipes hold togther better than others and don't require wrapping. If you do use casings, try to soak/rinse/repeat several times, especially the salt-packed type. I even soak the man-made casings, otherwise they seem to be pretty tough.
I heartily recommend trying out sausage making. I was wary of it at first - it looks like a lot of work - but the end product is SO much better than most store-bought sausage, and it really is fun to do.
This wouldn't be a post by me if I didn't include a link to a Good Eats episode, but it's got all sorts of good stuff:
A Beautiful Grind