The actor that would best look the part for Michael Vey would be Zachary Gordon because in the books Michael has dark hair and a bit of a smaller build. In the book says that Michael is skinny and kind of tall and he also Tourettes syndrome. From the description of the book it would seem that Zachary Gordon is just right for the part.
Guy Pearce would best play the character of Dr.Hatch. In the book Dr.Hatch is more of a taller guy with a skinny look. He is said to look serious and sometimes even scary. In past movies Guy pearce has been able to play the characters of men who are serious and strong leaders that will do what they have to, to get what they want.
The actor that could play the part Ostin Liss would be Noah Munck. Noah like Ostin is a bit shorter and in the book it says that Ostin is also a bit of a chubby and bigger kid and in past roles Noah has been able to play parts of characters like that. Ostin is also one of the smartest people in the books he is also Micheals best friend. Noahs personality and look make him just right for the part.
Actor Colton Haynes would play the part of Jack Vranes. In the book it says that jack is a taller guy that is also muscular and Colton has the look that makes him seem like jack. In the book it also says that Jack is Michaels bully but soon turns into his ally. With the way that he looks colton would be the best person for the role of jack.