I personally like training a SF (even though I train Big Men), and think training a SF is the best way to go. There's just a few things you gotta follow....
potential: for a SF you need very high potential to get a SF to where you need/want him to be. I like PAS (perrenial allstar) potential but more then likely you'd want a Superstar guy in it.
skills: can't have one jacked up skill at all, and if a skill is jacked up, it probably has to be one of the skills easier to train. for me, a hole in RB, JS or DR/HA is easy to fix. but skills like OD and ID are very hard to fix sometimes to where they can be efficient in that level. I usually go for a 5/5 guy to begin with at SF, not too low though.
time: you'd need to have a lot of patience training a 6'5'' to 6'6'' SF. It takes sometimes longer then others to train the players.
hope this helps
btw if anybody wants to train a big man, a Big Man with good secondaries are juicy on the TL and can give you a lot of dough.
3 Time NBBA Champion. Certified Trainer. Mentor. Have any questions? Feel free to shoot me a BB-Mail!