The advantage to using a Wall Plate Balun is that the Balun itself is "inside" a wall plate, instead of just having the Balun box next to the equipment. This should reduce the amount of boxes and thus leave a cleaner appearance.
You would simply install the wall-plate balun or, if you already have a balun with an RJ45 connector, exchange the balun that has the RJ45 connector for the CAT5 with our wall plate.