It doesn't matter what style the shoes / pedals are for. Shimano SPD pedals are for mountain bikes, I use them on both my Fisher and Lemond. I like them, but I have not tried anything else...
My bike mechanic (Blain at Xtreme wheels in C.B.) uses Speedplay pedals. They allow more float (you can pivot your foot more before it unclips) because he has bad knees. Shimano's have 4 deg. of float. Seems just about perfect to me.
I also have Shimano Shoes. They were under $80 and I like them just fine. They are mountain style shoes, so I can walk in them easy.
The first few rides clipless will make you nervouse. After you get used to them, you won't ever go back!