class d mono amps

hey guys, I need your help.  I have a semi truck that I am having trouble filling with good bass.  I am running an alpine 9813 head unit, kicker 850.1 4 channel amp to 4 satelite speakers(inifity's). I am running a kicker 800.1 stereo amp bridged to produce 800watts @ 4ohms powing 2 12" alpine type R DVC subs.  My problem is that i am not getting the "take your breathe away" bass that i am wanting.  My friend has these same subs in his SUV and they pound the heck out of you.  I have come to the conclusion that my semi has a much larger area to fill with bass as well as it is acoustically challenged.  So I have decided to go to a more powerful mono amp.  So here is the question - Given the choice of a Kicker, Rockford Fosgate, or MTX mono amp, pushing equal power, which is known for more heart-pounding bass?  Secondly, what is the difference between a class D amp and a class BD amp?  Any particular brand to stay away from? I have always heard that kicker was the brand for bass but i have been told that the new Livin Loud series are not living up to the kicker reputation. Any thoughts on this topic.  Any advice or recommendations will be greatly appreciated.  (also I am planning to have a custon box built. I have been told this can make a great difference, is this true?)  thanx Nightmare

out of the brands you listed i would go with MTX . and for the box a big differance. have a slot ported box built. also you may want to consider adding 2 more 12's or going to 15" subs.1974 ford pinto 4 15" punch Z power punch bd 1001 pioneer DEH-6700

in a semi truck you should probably look into 2 15's in a slot ported box designed for the subs and powerd to their rms rateing.2003 Chevy Avalanche,Eclipse CD7000,Morel Elate 5,Adire Extremis,Alpine PDX-4.150, 15" TC-3000, 2 Alpine PDX-1.1000, 470Amp HO Alt.