Have you thought about a recumbent? I used to own a long wheel base recumbent, and I was plenty low to the ground. It was a Tour Easy. Really fun to ride!

http://www.easyracers.com/toureasy.html

Townies are cute, but they are more for cruising around town on the flats. Not sure I'd want one if I had any hills to contend with. Not sure if you do or not. Of course, a recumbent won't fit in a trainer either....