Found out the following three Toyota part numbers will fit my car:
89170-16020
89170-16021
89170-16050 (being the most updated one)
I went to the junk yard this morning and found a 97 Tercel with the 16050 in it. The car hadn't been wrecked, so I got the piece ($22.99 vs. $675.45 at the dealer), put it in, started the car, and the stupid airbag light still stays on. Found a Toyota dealer not far from here that will do a free diagnostic on the airbag system for me on Monday. The local dealer wants $120 to do it.
Just my luck. The problems with my car are never the obvious fixes.
While researching this issue, I found a GREAT website to use for part numbers and fitment:
http://www.toyodiy.com/parts/