Bicycle Tutor

Hi guys, I'm 29 and have never ridden a bicycle til yesterday. It was a challenge but it was as scary and thrilling as you'd guess.
I have flat feet, so I stand/walk pigeon toed with the toes of my feet pointing outward, that said, I am finding it hard to find an agreeable position of where to place my feet on the pedals. I find myself resting the balls of my feet on the pedal, in order to keep any pushing power. When I do try to switch to the souls of my feet, my heels angle backward into the chain or spokes.
Are there any larger sized pedals I can purchase?
Thanks in advance,
-Richard
PS> Perusing the online stores I haven't seen any that seem to be larger than the ones currently on my bike.

You can get extenders to move ordinary pedals outwards =
http://www.kneesaver.net/
http://bicycletutor.com/go/916pedalextenders
P.S. The balls of your feet should be on the pedals as you say for better effective pedaling.