The answer to your question depends a lot on what sort of riding you do. But if you are basically a generalist who does a bit of everything (some commuting, some errand running, and some recreational riding) and if you are only going to have one pair of clipless shoes/pedals, then go with MTB shoes simply because they are the most versatile. They work perfectly find for road riding, MTBing, and everything in between. If you want additional shoes/pedals for additional bikes that are more specifically for high pace road or track riding, then buy road pedals/shoes as a secondary pair.

Riding brakeless is stupid with or without clipless pedals, but if I were forced to ride brakeless I would choose clipless.