Oh, as FlatSix911 mentions, other manufactures make SDP pedals (not just Shimano). But I only really looked into Shimano -- that was confusing enough (and I trust the brand).

Also, you can put SH-56 cleats on the non-Click'R pedals (and, likewise, SH-51 cleats on the Click'Rs). But you will need to pay extra for them (and we've already established that I'm cheap).