Well, I've got 3 Staffs so bit of a fan here, but should you (insanely!!) decide to go for another breed, how about a retriever such as a Flatcoat - beautiful beautiful dogs, have had 3 and would so love another one. Gentle, kind but also a bit bonkers too so should go nicely with a Staff!
Hmm, other suggestions....Boxer, Dalmation, Springer Spaniel, Water Spaniel...ooh, decisions decisions!
Oh heck, just go for another Staff!!