if you are just planning on doing the entire car, just get that roll-on/paint-on stuff. I got a 98 with a 5.2, dakota though, gets better gas milage than the 5.9, but not quite as strong. Very well designed engine IMO.
There was a guy that worked at a Circuit City insalling stereos and stuff around my town and he had 2 18's in his durango and his roof caved so much he had to brace the center of it. It was absolutely crazy loud. I think they were Orion's but its been so long ago I don't remember. I think it is probably one of the loudest setups ive heard.