I used to install professionally and compete, and IMHO, either is too much unless you are competing in DB drags. If you want to have that much low end, you would need MANY midbass/mid/high drivers to keep up with the "actual music" so you could hear it. In my competition setup, I had a single 12" in a small, sealed enclosure, with 6 1/2 midbass drivers, also in sealed enclosures, and a separate amp driving the tweeters. I had much more power going to the midbass drivers than the sub. Granted I was competing in sound Q, not DB drag, but it still stands to say that what you are talking about would sound horrible for day to day music listening, at least that's my take. FWIW, a friend of mine did 3 12's in a Camaro, and ended up taking them out after a few months because even turned down, the bass was overwhelming on a day to day basis. He had the money to change his mind, though. If you don't I would consider carefully before putting this much into your truck! Generally speaking, the quality of the subs will matter more than the number of them. Car audio is one of those things where you definitely get what you pay for. I've seen 2 10's outperform 4 12's, and sound better to boot. The enclosure design can also make or break your install, making expensive subs sound horrible if improperly designed and built, or making cheap subs sound decent if properly done. Just my 2 cents.
