got 12 jl 8w1v24's, cant decide on build

Hi all, new to the forum, name is Mike. Was introduced to this forum by a good friend in hopes of getting some education in regards to my system setup.

I drive a 2007 GMC Yukon. Recently I had this idea to build a system using uncommon, small subwoofers. I was excited and now after hearing so many different opinions, I am starting to get confused as to what is the most efficient way to set up my system. I got my equipment through the company I work for and cant return them.

Let me tell you what I have, and what I am looking to get out of it, and maybe you can advice me accordingly:

I have Twelve, JL Audio 8 inch W1v24 subwoofers. And I have an EXILE 1200.1 amplifier to power them up.

My goal is to gain as much SPL out of them as possible. My idea, which some disagree with, is to build a console box, staggering and downfiring the subs in a ported box. The port would fire directly at the firewall, under the dash. I have a total of 6.5 cubic feet to work with as far as air space. (Not area to work with, but I can get 6.5 Cubic feet into a box in the space alloted)

I plan on using 3/4 MDF and bracing the box every with 3 braces with holes them, every 4 subs. Shared space, single port.

I guess my concern is I dont even know if this is a good idea to begin with. I dont want to remove my 3rd row seat. I have 4 buckets so the only space I have to work with is from the dash to the rear buckets in the center. Or... behind the 3rd row, but then I would have to build UP, because the space is so tight and I cant fit all 12 subs back there.

I would sincerely appreceate any input you may have, thanks!

Well, I may have phrased it wrong. I shouldnt really use the term SPL here because I am not looking for SPL numbers or competing.

I guess what I really want, is to figure out a console box build that will get the most out of what I have to work with. In other words, Downfire? Multiple ports? Ports fire down? Back? ETC...

I know if I want Bass, I need to sacrifice Space, but I want to work with what I have, and I dont want to build it in a way that had I built it differently, I would have gained more bass out of the box. Thanks, aznboi3644, I really appreceate your comments, I can use as much advice as possible at this point since the build starts tomorrow.