Since you have a low arm slot and Velo on lefty, if say the sinker as well as any other FB variations that move. Definitely the slider and a change up if you can.
Righty: since you're over the top the sky's pretty much the limit. I'd experiment with a lot of different pitches and pick 1 or maybe 2 to throw. You can also just keep the 4 seam 2 seam slider combo and be fine with 3 pitches also.