EDIT: Just an FYI OP, every time I read your posts, I do it in Jim Carrey's voice. Thumbsup!
You should (I'm being serious) Do 1 IB sub, 1 Bandpass, 1 Ported, 1 Sealed. All of the same sub.
Car audio IS an addiction.
C.A.A.A Member #1
(Car Audio Addicts Anonymous)
I think there's a lot of really bad information being thrown around on this thread.
Give it a whirl, OP, if you think the sound of many different speakers all over the place is pleasing you'll probably be really happy. I believe in theory this could actually be made to work, but there's far more variables involved once you actually start packing multiple speaker systems in a car than "ported box plays lows and sealed box plays fast" or whatever other crap people think when they consider this idea.