If you want a stiffer SPD shoe that you can walk in, with plenty of room in the toebox for wider feet, i recommend these.
http://bike.shimano.com/publish/cont...road/2/SH-RT31
The Shimano SH-RT31. The Sole is stiffer then their MTB shoes, but not quite as stiff as their dedicated SPD-SL system shoes. So its still relatively easy to walk around in for short distances.
If you want a more secure strapping system over the RT31's two velcro straps, and have an LBS that can order out of a Shinmano EU/World catalog, you might want to check out the SH-RT81 with a ratcheting top strap, and two velcro, or the SH-RT52, which has a three strap velcro system.
http://cycle.shimano-eu.com/publish/...-.sh_road.html
http://cycle.shimano-eu.com/publish/...-.sh_road.html