Hi tpk and welcome to the Q&A Board,
I think I would stick with the Nikon brand flashes. Other manufacturers units may work perfectly well but if you opt for that route be sure to do your research. Using the wrong flash can fry your camera. Also there may be a need for a Nikon adapter to use a third party unit.
I would expect that you would need a off shoe cord (lead) to use the bracket. I don't think there would be a need for "additional equipment" beyond that unless you wanted to do something special or out of the ordinary.
I did a little searching around and found a couple of links that be of interest. Hope this a helps a little.
one linksecond link