It's a crapshoot. It'll depend on how much cash you want to lay out, unless you're going to get a prefabbed box for your subs, then make a decision based on that. Basically, since you're pretty liberal on the size and number, you can do anything you want. If you get a custom box done (from a really talented installer) he can basically do almost anything to manipulate the sound no matter what size or number of sub you have. The other question is how much space in the rear you don't mind giving up. Do you just want it loud, or you do you want it tight, or boomy, or super, super low. It's amazing how much experienced installers can do these days. Just don't get any CV Strokers! Also, the reason Nick's sounds so much louder is because the truck has way more air space allowing the bass waves to travel and get a larger in-cabin-gain. So, it makes it better for you to enjoy the sound, but if you're trying to bump really hard to be heard outside, then it's a little more difficult then like a pickup or something.
In general, it's easier to produce bass with say 4 subs at 100 watts each, than it is with 2 subs at 200 watts each, assuming as many variables as possible are the same.