ok, you are obviously choosing these JUST from what you have heard about them...so lets break it down....
heres the possiblity's
2 15" sx's sealed
1 15" 06 L7 ported
2 12" 05 L7 ported 2 12's will be louder than 1 15, so get rid of that
1 12" solo-x ported A close race with the 2 12's...but it would have to be an SPL setup...which might not sound to great...
1 15" DD 95xx ported pretty close with the 2 12's...but again..might have to be more of an SPL setup to get as loud....BUT closer than the SoloX as far as SQL, so we have 2 12" L7' and the DD 9515...Being a 15" it would be close.
2 12" type-r's ported
1 18" xxx-sealed.....
so its between the 2 12" type R's 2 12" L7's and 1 15" DD...Id say eliminate the DD just because for the price of 2 12" of either it will be about the same...if not cheaper, ( Depending on where you get them from). If you are buying online...you could find them for about the same price as the DD.. AND you have the cone area advantage...
anyone else disagree...go ahead and state why.
EDIT... and I just saw your from chi town...that stinks..I just threw away a dual 12" box for 2 type R's today...would have given it away for free...BUT this box wouldnt get as loud as 2 12" L7's or a DD 9515 INSTALLED CORRECTLY... (probably even if not)