The trainers I would have in the game and what styles/attributes they would help with are:

Emmanuel Steward - Style: Boxer/Puncher Attributes: Power/Stamina
Freddy Roach - Style: Boxer/Puncher Attributes: Speed/Power
Ronnie Shields - Style: Counterpuncher Attributes: Chin/Defense
Kevin Rooney - Style: Inside Fighter Attributes: Speed/Power
Enzo Calzaghe - Style: Unorthodox Attributes: Speed/Stamina
Lou Duva: - Style: Standard Boxer Attributes: Heart