Dan - There don't seem to be multiple tensioner part numbers for the 2ZZ, so I believe you are right in that all I need is a shorter belt.
I am going to go out on a limb and say that Toyota never offered an AC-less Celica with a 2ZZ engine (at least in the states), and given that - the local parts store won't be of any use without a little more effort.
Skip - I can do the measurement, no problem. I've done this before with a few non-factory belt routings. However accounting for the tensioner is a bit of a question, and I would rather not be off by a few mm's when I would hope someone could check in the engine bay and read off the part number!
DPM... 1600lb is great for an S2! Street legal in Illinois? I don't miss the emissions testing, personally.