Anyone who tells you to stay clear of wax on black or any color has no clue what they are talking about. Polish will get you the shine and depth you are looking for but ONLY wax will get you the protection that all cars need from UV light , acid rain, dird and bug droppings.
I have been doing this a long time and work for the leader in the business.
Who evers products you use is fine but make sure you use wax