From my own perspective it would be an interesting excercise.
My first thought was a level 7 coach but i really only have one trainee that would benefit immensely so i might not go that way.
I think i would drop the million or so it would take to buy an exceptional coach with a 35k wage.
Buy a guy like this
(19851183) for 500k and then drop 500k on a stadium upgrade with a breakdown of 960/300/25/3