Comfort should be your first priority. Having to reach for things can become distracting. As far as sound, that's personal preference. Experiment. Find what works best for you.
I suggest you keep the pedals that you use the most closest to where you are standing. Put the ones you use the least or that do not require constant triggering the furthest away from you. Try out a few different placements. You can always rearrange them at a later time.
