XS Power

So Im looking to add another battery to my truck as Im wanting to have no electrical issues. I have a 2003 Dodge Dakota crew cab with 4.7L V8 and will be recieving and installing my Singer 250 amp alt in about 2 weeks. I have a XS power D2700 in the front and a positive and neg run of Knu OFC 0 guage to back. My problem is I want to put a new battery under my false floor and only have like 6-6.25" max of height and about 16" depth by 16 width approx. I was going to get a XP2000 but even on its side I dont have the height, my question is: will running two XP950's be much less power than an XP2000? I know on paper its not much. Also will this be adequate for a Crescendo BC2…

So, I will soon be running a sundown saz-1500D. And now I have a aamp that puts out 190x2. So about 1900watts Rms total. I will be ordering a DC Power 180xp alt. And I was wondering what batt should I use in order to not have to use a secondary batt? Really don't want to have to do any modifications if possible. I drive a 1994 Toyota Camry V6. Thanks. -jonathan

2009 Dodge Caliber Srt4. 2.4L turbo engine.