What size motor are you planning on putting on it? Like somebody mentioned one transom height is more commonly found on used motors, than the other. That being said, there is a cutoff where shorts are more common than longs. If you were looking for a 15 - 20 hp motor, short is more common. If you are looking for a 30 - 40 horse motor, long is more common. 25 seems to be a crapshoot, without one showing much more than the other.