Four subs, two different port frequencies

So I recently ditched my 15w0s in a fourth order bandpass for an opportunity to actually make money by picking up four 12w3v2s.  I loved those fifteens, the box they were in was well designed for the subs and was incredibly loud, my only problem with it was the poor response curve due to the bandpass box.  It was never anything that really drove me nuts, but some songs just didnt hit quite right (pretty sure it was tuned at around 33hz).  Moving to these 12w3s which I have had lots of experience with and absolutely love the sound quality, Im in a big dilema of sealed vs. ported.  The sealed box would truly do these beautiful subs some justice and give me a nice smooth response obviously, however Im a total bass addict and really want to see what kind of damage four of these guys can do in a ported box.  My brother has the two 12w3v2s that come in the JL H.O. box (the red carpet in the middle with the subs at 40 degrees towards each other), and for a ported box I have to give it credit, very very smooth response, still some dips but overall great sound.  Well today I was thinking and realized that with four of them I could actually probably tune two to one frequency and two to another, hopefully balancing out the frequency response across the range and giving me and overall smooth yet very loud sound.  Would this work? Do you think its a worthy idea? If so then maybe what frequencies what you guys recommend tuning to?

Thanks,

Jeff

Think about it...if you tune two to one freq and two to another freq there will be a common frequency that these are tuned to.  Might just as well tune the lot of them to the same frequency.

These woofers will do well in a sealed box.  If you want to port them the port will probably have to be a bit on the large side.

haha yeah I assumed it would be one of those two responses, just on the off chance that it would actually work out like I had hoped and would solve all of my problems.  I have already figured box and port size for ported and sealed boxes and either way its massive, will have to fill most of the back of my car.  Anybody on here have any strong reasons against an upfiring box?  Im not particularly fond of them but this would save me a ton of trouble on trying to fit them all (going in a 99 expedition, not quite as much room standing up as you would think), especially if I do go with a ported in the end.

Thanks again guys,

Jeff