Well you mention $400 for subs, but I don't think you fully understand the cost of setting up SPL system designed to hit you're seeminly arbitrary 148db mark. How much money have you set aside for replacing the alternator and the rest of your stock wiring? As mike said, you're going to need some powerful amplifiers to get that loud. The benchmark for a reliable amp is around a dollar per watt. Of course you can get it done for cheaper than that, but my point is that this system done right is going to cost you a lot.
audiobahn amps are also very reliable that have cooling fans and other features that will not let down your subs. They are also not as expensive as kicker... in my opinion kcker subs are way over-priced i have an audiobahn A8002T amp that is 800 watts RMS bridged that i got for 200. a 200 dollar amp from kicker will be alot higher than that. i reccomend audiobahn than anything, i have not overheated or anything and i am running 2 compr vr 12inch subs bridged in parallel.
You should expect to spend atleast close to 1k for the amp that you want to power. Look around for some good used amps in the shops sometimes people trade them in because they do not know what they are turning in.
Or brand new you will spend 1k if not more.
I personally have a us amps 3000 and I have not put it in because I have to upgrade my alternator because I will need atleast 250 to 300 amps minimum to power this thing.