The fixie strap doesn't hurt. You can tighten it or loosen it for retention vs. comfort. There are lots of different fixie straps out there. I just linked to that one because the price is pretty good. I picked up a set for myself, and they appear to be rebranded VP 001's (which normally sell for about eighty bucks) with the strap.

You might want to think about just getting two sets of pedals; the footsoldiers and something like these origin8 road pedals which are cheap pedals but they're only twenty bucks. It takes about 3 minutes to swap out a set of pedals so you can use the platforms when you're bopin' around town and put the toe clips on when you feel like you need more secure retention. My prediction is that you will like the platforms so much that you just forget about the toe clips, but you never know. If you end up using the toe clips all the time you can spring for a nice set of MKS or maybe even give clipless a try.