There are a number of "flat foot" bikes out there. Electra makes several variations. Trek has their Pure model. The Giant Suede is another. Technically the best are the RANS crank forwards, but those are pricey and I don't think are quite as stable as the Electra and Trek models.

Some examples from Trek:
21-speed with hand brakes, step-through:
http://www.trekbikes.com/us/en/bikes...esportlowstep/

21-speed with hand brakes, men's bike:
http://www.trekbikes.com/us/en/bikes...ure/puresport/

3-speed with coaster brake, step-through:
http://www.trekbikes.com/us/en/bikes...deluxelowstep/

Electra:
8-speed internal hub with hand brakes, men's bike:
http://willybikes.com/product/electr...-8-51799-1.htm

8-speed internal hub with hand brakes, step-through:
http://willybikes.com/product/electr...-8-51800-1.htm

21-speed with hand brakes, men's bike:
http://willybikes.com/product/electr...21-51780-1.htm

21-speed with hand brakes, step-through:
http://willybikes.com/product/electr...21-51783-1.htm

3-speed with coaster brake and front hand brake: step-through:
http://willybikes.com/product/electr...-3-51795-1.htm

7-speed (derailleur) with hand brakes, men's design:
http://willybikes.com/product/electr...7d-51786-1.htm

This is the Electra page from one of my local bike shops where you can see all of the above and more:
http://willybikes.com/product-list/e...53/?startRow=1