From what I have read and some people I have talked with say the Key to a good Motion Offense is having 5 guys who can Handle the Ball, Hit a Jump Shot, and Pass the ball well. Look for guys (Big Guys as well) with JS ability, Handles, and Passing on top of the other things you would look for.
The Key to any defense is having you 2 Guards with high OD, your SF with High ID and OD, and your Big with high ID.
For the type of setup you look like you want I would prioritize JS over IS on your bigs. You still want decent IS but if you found a big that was a 10 in JS, 10 in IS, and 14 in ID I think that would suit you better than a guy that is 6 in JS, 12 in IS, and 14 on ID saying the handles and passing abilities are the same.