humble customs

I have 2 audiopipe bdc4 12s, recommended airspace is 2.5-3.0 cubic ft if air per sub, I want to do a blowthrough box max size of the box is 60 inches wide, 20 inches deep, 24 inches tall. Going in the bed of a 08 sierra ext cab. I heard that a 4th order would be best for getting windy but im not super knowledable about the box building side of it.