Clyde,
As dueroute said, there are a plethora of older bikes that would fit the bill quite nicely, depending on your personal preferences. If you're leaning towards a Hybrid, I would personally lean towards bikes like the Specialized Crossroads, Miyata Triple Cross, or the Trek Multi Track 730. All three of these were good, solid Hybrids that were equipped with serviceable components, and came in smaller frame sizes that would accommodate your build nicely. They also have the handlebar set up you desire, with flat bars and relatively upright riding position.
As far as MTB's go, There's nothing better than a late 80's or early 90's Rockhopper or Stumpjumper as a commuter. There are creampuffs out there, and there are ones that have been ridden into the ground... but they're plentiful, and relatively cheap. Pay close attention to the suspension; many of the older forks don't have a good spare parts pipeline, and the fork could be shot, so look for one with a rigid fork instead.
Save the 2 x 10 and IGH drive trains for a future project; the high tech nature attracts more attention to your bike as a target, which is exactly the opposite of what a commuter bike should portray.
(Just my personal opinion.)
Last edited by oldskoolwrench; 06-28-14 at 12:32 PM.