Kitchen aid grinder/stuffer will work, but it is very, very slow. I wouldn't be making sausage at all if that's all I had...not a good experience. As for stuffing, a piston stuffer is the only way to fly.
I have LEM #8 grinder that I got from their refurb section and it works great. I have to try to keep up with it, not the other way around, and it was a $99 grinder. No problems at all grinding 20# of meat for sausage. I think 20# may have taken 10 minutes...maybe. They've got an $88 one in their refurb section now:
http://www.lemproducts.com/category/refurbished-products For the home gamer, that cheap one is fine. If you plan on grinding more than 20# of meat at a time, you may want to look into one of the big bite grinders. You'd be surprised how fast a #8 goes through meat.
I have a 25# meat mixer, it is nice. 10# minimum for it to work right. Really good for those 20# batches. I got a 5# stuffer from LEM on the same refurb site, looking back now I probably should have got the 15# model. It's not hard to fill, but when doing 20# of sausage it would be nice to just fill twice instead of 4 times.
For hand mixing sausage, I use a pair of thin cotton gloves, then pull nitrile gloves over the top. Cheap n' cheerful, and insulate great for cold or hot.