ZARS will let you on track in jeans for the first couple levels, though they still (highly) recommend riding pants. Most people show up in riding pants, though there's always a few pairs of jeans in the crowd.
Check Bob's Cycle Supply on 36 and Rice for overpants. They've got the best selection in the metro, and don't gouge you on price.
Also, DCTC is a wonderful course for riding schools. It's nearly all curves, with only two real straightaways. You'll spend more time learning to turn than anything else. Since cornering is by product of a multitude of individual skills, a proper foundation of cornering will keep you upright for the long haul.