depends if you wanna do it yourself or send it in for him to do it. Idk what he charges for a recone if he sends it to you you'll have to ask him. If he doesn't have the dustcaps for the HX2's i would hit up dave @ PSI and see what he can do for you
when selecting a battery for a system that will be ran when the car is running, you want a battery with a very low ESR .
i don't recommend using a system of this caliber with the car off ever unless you want to but 12 huge deep cycle batteries and you can charge it for 24 hours after play..