Is single speed an option? That'd be even better.
Check out bikes w/Nexus hubs. That'd make for no derailleurs.
06/07 Trek SOHO (700 wheels)
New Soho 4.0
I'm curious to see what you'll find in a stock single ring, multispeed bike w/26" wheels.
Singlespeed would probably yield more flexible results.
I did just find this though:
Specialized Globe Centrum (Elite IG3 or Comp)
Flat bar, 26" 3 or 8 speed rear hub, disc brakes. Never looked at those before.
Good Luck.