I use platform pedals (specialized Bennies) so that I can use regular shoes. They do make casual looking shoes that are SPD compatible and most likely crank brothers eggbeater type of pedals.

Another thing to consider is to get a bike fit to see if they can eliminate or reduce the knee pain you mentioned. I used to have some knee pain after a long ride and I too thought my saddle height was correct but after the bike fit I found that the saddle was 1.5 inches too low. I now ride pain free. Just something to look into.