You're going to be playing quite a bit of catch up to make him just into a serviceable small forward. It would be better to focus on training him into a solid power forward or center.
This thing is I took a look at your roster and you've got quite a few trainable guards you could work with or even a good looking power forward in Torben Weithase. These players could all be a much better option to train then your 6'6" guy.
Christoforos Athiniotis, Erik Kala, Albert Elorza, Antti Sarjamo, and Will Hendrickson all are 19 or younger with at least allstar potenial... They're your best bet at training.