When it comes to BigMen and Handling(and driving and passing) while playing LI and LP, here´s my take.
Even thou the two inside-tactics are nearly alike, there are a few things that differ.
Low Post requires more Handling on your big men to execute the tactics to the fullest.
I believe it´s because they post more, backing up a defender, make a move and shot.
While in Look Inside, the big men require more Passing.
This is because they kick the ball back out(passing the ball, not driving/dribble) if the don´t have a good opportunity to score.
I try to find(or train) Bigmen with atleast 5, but preferably 7+ in Handling and Passing.
But the ground rule is still, Handling>Passing you're better of running LP with your bigmen.
Passing > handling, you're better of running LI.
I think you can afford to lower your IS by one or two steps, if you can get Driving, Handling and perhaps passing up a few steps. He will be as efficient, maybe more, than a bigman with slightly higher IS but low skills in Handling/passing.
So the perfect TO is a young, "tall" PG with atleast Superstar potential that have high Passing and some Handling and Driving. Train his IS,ID and RB and round it all up with som 1on1 =) Add some OD and JS/JR and you might have yourself a NT-player =)
As always you cannot measure a single player just by his skillset, you need to look at his role on the Team.