15" btl box recommendation

[penguin3820 0]

I have a 2004 F150 super crew. I dont want a blow through and I am thinking about taking out the middle rear seat and putting a center consoled 15" there. I currently have 2 10" Qs under the back seat but I wanna go louder so I need someone to help me design something width needs to be 17" - 17 1/2". and height there is plenty of room id like to keep it under 30" and there is enough depth for 30". Iv been messing around on the rockford boxwizard and im looking at possibly a wedge type design with a flat on the back top of the box with aero ports and then the front facing sub.

[penguin3820 0]

ALSO,

I have a question in terms of battery. I have a 260 amp mechman alternator. I am running an hk4000d and going to be a big 2 channel amp havnt decided which one currently just a p400.4. In terms of a battery would I be ok with just a d3100 up front for now and then get a 2nd battery when I have the cash?