I was looking at those clip ones that take special shoes, but I am confused about how they work. Do I just buy those Shimano pedals with the Shimano cycling shoes and that's it, out do I need something to attach the shoes to the pedals? Are brands interchangeable, or do I have to match Shimano pedals with Shimano shoes? I like a pair of pearl Izumi shoes, but would want the Shimano pedals....