Although that is a neat feature from Tirerack, I don't like the wheels it matches for the Trac.
One of the best 20's I've seen on a 1st gen Trac is Patrick Pierborn's. He has the chrome ones but they're also available in silver. They're called "Splice" from Verde. Here's a vendor that carries them (they also carry other nice wheels):
Edit: The page isn't refreshing right or something, just change the wheel size selection to another size then change it back to 20. The page should refresh and show the wheels.