I have Shimano pedals on my commuter/city bike that are platform on one side and SPD on the other. I have SPD on my road bike, so these were a good option for me to ride either clipless, or to just jump on and go if I wanted to do a quick run to meet up with friends and not have to fuss with taking extra shoes to change into.

Just an option to think about. It would let you have the platform that you want for now, but give you a chance to ease into clipless as you got more comfortable.

I think these are the ones I have:
http://www.amazon.com/Shimano-Road-M.../dp/B0000C83XY