Originally Posted by canyoneagle

Okay, the edit on height and inseam really helps narrow it down.

You'll be limited on bikes on the used market for sure - but not completely out of the picture.
Mountain bike frame size will be "extra small" or 14" or so. Road/cyclocross/hybrid frame size will be 45cm or so, which is extremely hard to find, if at all.

This bike is a possibility, in the "extra small" size http://www.bikesdirect.com/products/dawes/lttour.htm