I love Kelvin Harmon. Not as explosive as Metcalf or big but he's probably going to run a 4.5 and he has good size at 6'2 216. For a junior he's got the nuances down on playing the position.
Check again on Metcalf though. Other than the size and athletic ability his biggest strength is his release and the separation he creates and unlike AJ Brown who strictly plays in the slot he's always on the perimeter. He only runs three routes at the moment but he's a mega talent.
It's more likely we're going with Ed Oliver, Clelin Ferrell, Josh Allen or Greedy Williams with our first pick anyways.