Put the two deepcools in the front and use the fractals in the rear and top/rear. The stock fans don't push a lot of air so this will give you the positive you're looking for.
I have build in an R4 and it is an excellent case. Very easy to build in too.
Edit: I should have added that the rear and top/rear should be exhaust.
If he wants a positive pressure airflow system, then the top rear should be an intake fan, not exhaust. I have 4 Noctua fans inside my define R4 and have two intakes in front, intake on top (with filter) and exhaust fan in rear.....this setup moves a lot of air inside and also prevents dust buildup...Highly recommend!!
also, the Noctua's are super awesome fans...they move a good amount of air, are quiet and very well built (6 yr. warranty).