You want good OD and ID because sometimes you will have to play him outside def, and sometimes you will have to play him inside def (if the other team puts a PF type on SF position).
Offensive skills wise, you want JS for outside offence, but you also want good HA and DR and PA and IS. Basically a good SF has good levels in everything, (except JR isn't as important I'd think) and any good SF you get will cost you a pretty penny