(6) sa8s and an 01 Impala

So I got rid of my sa15s and getting (6) sa8s. They are going into my 01 Impala. What kind of box would give me the best results?

I am aiming for a daily box (30-34hz tuning) although I do compete in TNESPL. The sa8s will be powered by a RD3250.1.

Anyways, what would yield best results? Subs up/port driver? Subs up/port back? Subs forward/port driver? Subs/port back? I may do a 4th order also when 80 gets back to me.Things I will not do are seal the car off from the trunk. My absolute max dimensions are 34"L x 17"H x 24" D

Any and all help is appreciated!

BTW both my rear seats fold down.

Also mods, if you think this will get more replies over in the SA section, please move it there. Thanks.