spl competition econoline van

Hello, I was looking to see if any one had any experience with walls in van especially a mid 90's ford econoline van. Last season I ran a wall at the B pillar with 4 12" kicker L7 woofers mounted on the passenger side and port on drivers side of the vehicle(left). Didnt have enuff power to the subs i now find out to get good numbers highest i scored last season was 149.4 certified score. After season ended got a hold of a diff amp and increased my numbers. But for the 2008 season I am up grading everything from woofers batteries wiring and reinforcing box with steel. I have replaced the l7's with four 18" RD subwoofers. Upgraded batteries from 2 basic rv/marine batteries to two cactus 9000's running more runs of power wire, and upgrading the amplifiers from 2 d2400.1 directeds to a few stetsom 7kd's. <p>

My Question is for any tips with larger vehicles like the vans. initial box curently is 30 qu ft. going to do trial and err down sizing  and adding wedges to find the qu ft the subs and van like. Have been told to use larger box with less pwer and smaller boxes with more power. And how many of you have ran multiple runs of power wire to acomidate for the amperage that is being sent threw the system. should a guy go by what the wiring chart says that lefts say 1/0 wire can handle well depends on what chart you look at but on average is supose to handle 300/350 amps. if i am going to be burping lets say a ballpark of 3500+ amps should i have at least 12 runs of +/- power wire? thats not even figuring in curent loss for distance. and when is it to much wire? by specs the cs 9000 battery will sortcircut charge 9000 amps am i suposed to have that much avail amperage in wiring?

Thank you for the confadince build so many people are telling me that it will never be loud. and use a caravan or astro or other.  But to me it was was avail and got a great deal on it its large enuff when i put 5k  miles on this summer basicly back n forth between bordering states i camped in the van or tent at campsites. so it has been wokring out for me affordability wise vrs hitting hotels for every show. 

Yes i plan on running street max . And have talked to Alan about the 12 volt versions. Planning on prdering the cactus 9000's this next week the only other battery i have ran acrossed for extreamly high and fast discharge is the spl cell batts but considerable amount diff  in price. And another question pertaining to power wire. "X" brand of wire  has or that im considering 2 diff series of 1/0 series "A" is 5145 strands of pure oxygen free coper weighing in at  .42/foot and at$3.25/footrated at 300amp, Series B wire on the other hand in 90% aluminum and 10% copper with a rating of 250 amp weighing in at .2 / foot  and price at $1.75 / ft. In reality a guy would prolly want to go with series B wires bc of the cost for running multiple runns. for speaker wire last year i used 8 agu. And what worked good to run my jumpers and leads was using 4 agu ring terminals splicing together that way and taping the hell out of terminals for exctra security, vrs trying to stuff dual wires in sub terminals and having to crawl in the box to fix it inbetween runs. Basicly money talks but is there any drastic differnces between copper and alum? as in wire or buss bars?the drop should be min correct?

I plan on doing steel structure (2" tube)for final box. lessen the flex.

Thank you for the input and looking forward to more if you or any one else thinks of anything.