I did a search on SearchTempest.com
http://www.searchtempest.com/results...min&maxAsk=max
Here's a GT. Has front suspension that isn't ideal, however, not the end of the world, either. Already has road-type tires.
http://sacramento.craigslist.org/bik/4234081272.html
I don't remember frame sizing in inches. Here's a 20". Thinking it's too small, but someone may chime in:
http://sacramento.craigslist.org/bik/4230607908.html
No idea of the size:
http://stockton.craigslist.org/bik/4213023668.html
Looks pretty nice. Seats can be found cheap (and groveland is a great little town!):
http://goldcountry.craigslist.org/bik/4196010510.html
Blurry pix:
http://sfbay.craigslist.org/pen/bik/4236695329.html
Also, look for Trek FX bikes. They have a great reputation for Clydes.