I also agree that Jack Plotnick would be a great Red John. He is a great actor and he is able to play RED JOHN perfectly. 

I really hope Brett Partridge is RED JOHN. Jack Plotnick will surprise us how he will be playing RED JOHN. You will see there will be no better choice than him. And if Bret Stiles is really RED JOHN's father - two great actors will not dissapoint us.