Lol ... I think all those are intended to be the same size. We went from one tire size convention to another some time ago ... back in the 80s, I think. Why? No effing idea! Here's some info on it:

http://sheldonbrown.com/tire-sizing.html

Re the stem length ../It depends on how deep your rims are. Deep (aero) require long stems or they don't reach long enough away from the rim for you to pump them.