The definition of a road shoe is one that can accept the large road cleat. Those Shimano "road" shoes are not "road" shoes as they have tread on the sides (a road cleat is to big for there to be tread on the side). All those shoes are mountain bike shoes.
For example, here's what a road cleat looks like mounted on a shoe:
That being said, a mountain bike shoe is probably the best choice for a beginner due to the greater ability to put your foot down and get a grip, or walk around in them (because they don't have any tread on the sides in the front, road shoes are slippier to walk around in). Um...as you mentioned. :-)
So all those shoes should be compatible with the same cleats, aka any mountain bike cleats. If you already have mountain bike cleats and you like them, stick with those. If you're buying new ones, I personally recommend the Cranky Brothers pedals (eggbeaters, or the other variations of the pedal) or Time ATAC due to the increased float over the standard Shimano SPD's. In my opinion, of course.
Prices listed are for a pair of pedals. I don't think it's even possible to buy a single pedal by itself, they always come in pairs.