Welcome to YorkieTalk
You can use any dog shampoo you like. I would stay away from Hartz products though (animals have died from their flea products). Human shampoos aren't recommended because they dry out their skin. The two people shampoos you might be able to use are baby shampoo (Johnson and Johnson) or Oatmeal shampoo (Aveeno or something similar). These are the two kinds I use on Ellie.
I just use a regular harness from the petstore.