Could be any of those. It really depends on the individual.
How old is the horse? What is easy/difficult for him to do? I ask this because when I got my gelding, I rode mostly western, but he really wasn't the best western horse. He is more up in the neck as opposed to stretched down, he has a reaching, faster paces stride naturally, and all sorts of other little things. When the girl leasing him began riding english - he BLOSSOMED! He loves jumping, looks great in the gear and doing the maneuvers.
Maybe try it all out, and see where his niche is??
Well to tell you the truth I ride english from the time I was 4 years old to 12 years old but then I got tried of it and I want to do western & Rodeoing but im glad I did to english first to herlp my balance wise.. its the best way to start :)