it's been a long day...
i kinda thought the same, i would say maybe 3.5 per. i was going to run 3k to a single NS and jacob told me at 3-3.25 for my ns 15. about your electrical i would 2-3 batts and you should be fine. 3 will be safest. and about the other amp yes you can run them off the same rear batt and be fine.that box is to big