6'0" will be the shortest player to record a dunk because we've traditionally never listed a player under 6 feet on our roster (even if he were only 5'10") in the era of dunking.
Doubt Chad Estis or Gus Johnson ever dunked -- they were each about 6-0.
Spindle Graves was listed as 6'1", but I find that questionable.
I would prefer the HEAVIEST player to dunk. That opens it up a bit more, with John Beauford probably having a slight edge over the Baby Bull Vic Alexander.
It's debatable whether DJ got one in a game. There was a breakaway at home against Robert Morris in 2012 where he got some rim, but not at all a throwdown. You tell me:
https://www.youtube.com/watch?v=veyL0U8S-bc Stevie and Bean could dunk in warmups.
Sheldon, EJ4, and Ike all had comfortable dunks in warmups last night, but have yet to do it in a game. Sheldon can get up easy if the ball is set up for him, like if he lobs it to himself. I predict if he ever does dunk in a game, it will be a tip or alley oop.