The way I did I made it an armor bonus and a separate insight bonus totouch ac. Armor bonus doesn't stack you only get the best one, and you still have the line in weapon and armor proficiencies about losing the ac bonus and fast movement if he uses armor. Also armor bonus doesn't enter into touch AC so I think it's better to have a separate bonus than make a distinction for the monk.
About the styles, my group cancelled play today so I have lots of RPG energy to spend on homebrewing stuff. Glad you liked.
Quivering palm actally works the same way. Even in the old monk version you could activate it in the same round.