Yep, 16" is standard. Tire size varies on trim and options. I run 235-70-16 (stock size on mine). I live in North Dakota so I do have some experience with snow tires. I had nokians on one of my cars 2-3 years ago. They were good. The vehicles I've driven with the michelins I have not been impressed with at all especially for the money, although they were actually pretty quiet I thought. I would definitely go with the nokians of those two. With the exception of some Pirelli's I've had, the blizzaks have been the best I've driven on for pretty much any vehicle (car, truck, SUV). I really have been pleased with them.
However, I usually don't run snow tires on my trucks if they are 4wd. I pick a good all terrain tire. My choice is strongly influenced by the tire's winter performance. If I lived in Arizona, I'd want an AT tires with better sand or rock performance. In Georgia I'd probably want better mud performance. Here, I want a good AT tire with better winter performance. I have been really pleased with the tires I have on the liberty ('02 sport 4x4) now. They have done everything well but handle the winter conditions better than most AT's I've run. I really have been impressed with their ability. Snow and ice traction is great. They are 235-70-16 hankook dynapro AT m's. they perform great, have kind of bulky aggressive look. Road noise isn't bad. My new choice for AT tires for sure. I've run several sets of Firestone destination AT's on hunting trucks and really like them also. Great winter tire and good AT performance. Not as aggressive as the dynapro so quieter, but Avery good tire. If I picked up another liberty, I'd put the fynapro's on it with out question.
Hope that gives you some ideas and helps you.