I would cut the iPad & TV out completely! When he finally figures out it is really not an option any more, he will find something else to do. This will probably be harder on you then him (unfortunately) but I would be shocked if didn't have a positive impact.
Other thoughts...
How much time does he spend outside every day?
Have you thought about some unstructured, structured activities... like a Steiner playgroup for example.
When will he start (pre-)school? Mine tend to act up when they are under-stimulated.
Sports? (e.g. Swimming lessons)
