I'm 6'3" myself. A 88-89 seat ht, pegs down and back a little, and play with bars/stem combo. I think the rox risers are a good idea as well depending on bars and stem combo. There are so many different possible bar height and stem combinations. A taller bar will also go more forward naturally then a short bar when in it's nutral position. For a lot of taller stem short bar combos a 1" forward stem still won't get you back forward enough. When you go back a bit on the pegs it will also give him more boot room with the shifter and brake pedal that can be kept that way if needed.