SIr
Have a W12 PRS, it has the best SQ, W6 comes 2nd in SQ with some power and Type X is a compromise between W6 and W7, it will give you a lot of power while still remaining true to SQ, handy for competing with those 2 X 308 mainstream setups.
Ask Mr smartboy_am<SCRIPT type=text/javascript> vbmenu_register("postmenu_119405", true); </SCRIPT> high chance are that he can source you out W6.
Or else I will try.
Look for the polk MOMO and SR SUBs, no one can beat them in price/quality, even the mighty Type R and CVs and they are the only SUBs which can be distinguished between Alpines and JL Audio, having a unique note, I believe they are available in Lahore or you can also source them from Karachi.
Also look for P1224, if you are tight on budget, exceptional build quality and good sound at unbeatable price, 12-13K maybe.
W12GTI is also very good on SQ, ultimate JBL.
Everything depends on price at which you are getting the SUBS.
Regards