How much battery do I need?

[PerfectionDtail]

I will be installing a 4000-4500 watt system, all new Rockford gear for subs and amps and MB Quart for highs.
My boat has 2 motors and I currently have 4 Interstate batteries for those. The stereo batteries will be in addition to these and be for the stereo only. The alternators on the motors are 60 amp (weak).
I have been all over with this and I am trying to figure out what to use. Any help would be greatly appreciated. I want to eventually get the Honda generator to keep onboard, but not right away. So until I actually get the generator, I want plan A to work for the time being. Here is what I am looking at, if anyone can help guide me, I am thankful.
"3" - SVR Batteries (this is the info of 1 battery):
Voltage 12
Reserve Capacity 190
Amp Hour 100
CCA* 1100
Max Amps 3550
Weight 72lbs
"6" - Rockford Fosgate batteries(specs for 1 battery):
1100 Amps
Reserve capacity: 50 Ahr
Lifeline 8D Battery
162 lbs
1675 CCA
255 Capacity Ampere hours (20 hr rate)
I think the SVR are the way to go, but I dont know for sure. The appealing thing about the Fosgate battery, that is there is a problem, it is the easiest to replace and they have a 18 month warranty. The lifeline is huge, so would one be enough? I will also install a charger as well.
I have no idea on the stepup I should use so please help. Thanks in advance.

[ROZ]

2 or 4 good 6volt batteries will do you good if you plan to be the DJ all day long....
If you're seriously considering the 8D battery, PM Locogringo eith here or on RiverracerX.com ... He has one that powers 2 700 watt amps... I think he has run his system up to 3hrs without any problems...

[PerfectionDtail]

[QUOTE]Originally posted by ROZ
[B]2 or 4 good 6volt batteries will do you good if you plan to be the DJ all day long....
Roz,
Which ones (6v) should I go with? Which charger for these. Don't plan to be the DJ all day, but I want to plan for the worse/best (however you look at it).
Thanks for the reply. I am doing this in the next 2 weeks so I want to get the battery area in the back ready for more battery.
By keeping the 4 batteries on the motors, will the alternators charge any of these batteries at least a little for the stereo?
Thanks again.

[PerfectionDtail]

Anything else????????