Steven Adams is more probable, not the shot blocker or offensive player that Dieng is. Jeff Withey is also possible, good offensively and blocks shots, rebounding is not great but improved every year. Lucas Nogueira is also possible, although he would be better to acquire as a 2nd round pick.
Dieng is clearly the best option among the bigs for the Knicks because he has upside on the offensive end but is still a monster on the defensive end. We could also end up quite happy with Withey or Adams.
I really like Kabongo at the PG because of his low turnovers and high IQ/vision/leadership. I like him more (for the Knicks) than some PGs with better stats because of this. Unfortunately, Kabongo may stay in school, although the Knicks should keep him in mind for the 2014 draft, along with Patric Young.