well lets see not to be a arse here but when you got 2 15's an at least 2k of power your gonna break shit no matter what you do.
i have talked with several ppl that have broken brake lines, an anti lock break system faluire, my own dash instrumental lights went out. jp was ripping sheet metal, twisted is haveing roof problems an he broke out his windows in the back. so be prepared for something breaking.
now as far as the box goes if your going for daily an want good numbers what you have is prolly gonna be it, anything else an its a spl box an won't really do as well for daily except make alot of noise an won't get low like you like it.
good luck with what you go with though bro but i would just keep what i have if i was you. your doing 150's with a daily box