Yes, the Lake sandals I purchased are very stiff under the ball of the foot and are clipless (SPD Compat).
The bolt seems to be a 10-32, so I'll just pick some longer ones up from a local hardware store and cut them down to size, we don't have any at work that are threaded fine enough for this application else I'd just make use of what we have.
I wore them in to work today. I had to drive in because of a dental appointment I had before work. Wow were they comfortable. I could hear the cleat grinding into the pavement as I walked and they now have some scas on them... oh well, just makes them look meaner