Changing '75 international to clip in pedals and shoes I have developed foot issues because my stiff insoles don't do me much good on the bike, especially if I stand to go up hills. So I think I need to switch to clip ins with good stiff shoes (Bont looked good online). What issues will I have with my Campy cranks on the Raleigh International  and Suntour on the Specialized Hybrid ? I am hoping for one pair of shoes that I could walk around at the grocery store in and ride on both bikes.

Mountain bike Look pedals? The Bont commuter shoes sounded like just what I wanted till I saw they were discontinued.
I would just pull one pedal off each bike and go to a bike shop.  Go with the right pedal as the threads are normal.  I seriously doubt either has odd threads that you cannot find clip pedals.  You would just get compatible (or same) pedals for each bike.   Pick a pair of shoes that walks OK.  A mountain shoe is going to walk better so you should get mountain pedals.  Shimano SPD and Crank Bros Egg Beater are two popular types.

A hard soled shoe (without clips) designed for biking with larger platform pedals is also an option.   They don't bike as well but they walk a whole lot better.  Five Ten is a brand.