The a6600 is a big honker for 75×6 and unregulated . If you try to run it on the edge ,bridged or all 6 channels on 4 ohm but low 4 ohms it will suck the stator right out of the cowl of that merc .
the subs you selected tells me alpine pdx wired to 4 6x9s . 500.1 for 2 polks. You can wire the 2 polks to 8 ohms each than parralell to a 4 ohm load at a 500.1 and it would sound pretty good . And draw sparingly from your electrical.Unless you listen to rap .remind these guys you have outboards .

4 6x9s installed properly with clean power wont need full tilt sub action to round out the sound

this is my original thought with the 6 - 6x9s
for them to carry most the sound with clean power put to them with the jl amps and head unit
and just use the subs with light power just to add a tad thump
actually I screwed up when bought the 12s and didn't pay attention they were dvc speakers
so either buy 2 more or just use with 1 voice coil at 100 each
just trying to wire the best way for what I got and test how long battery last during day
as why I got the big 31 deep cycle series for radio
I wont be using the 2 360 amps
1 new in box and 1 used so if any1 needs them

also why I wired radio to 1 battery only so not to suck out the small charging system
and if play stereo too long and suck battery,,,,,
motors are isolated from it not to drain them to start

boat was a race hull set up for v8 omcs
the 3 2.5s are lighter than the 2 8s
just in the dialing in stage so not fully strung out yet
with 3 28 cleavers stopping motors at 8,000 she is scooting
and the 28s are not loading the motors enough,,,lol
getting outside motor heights right to keep transom stuck,dialing in props
figuring cg it likes is the stage im at

Ok first forget about the 6x9's under the bench, unless you plan to lay on the floor to listen to them. They are a waste of speaker and power there. Get your speakers up as high as you can in the sides. They will cover better and sound louder.

Honestly if it was me with the amps you have, I would not even try to run those Polk subs. You will run more risk of blowing a driver than anything, unless you are real carful on setup. Even with the amp running at full output those subs are not going to be doing a lot. You will just be wasting your time, and if you push that amp to hard it will smoke those subs. Either change subs or change amp to match better. It is not recommended to run just one Voice coil on a DVC sub.

Even using those amps on the 6x9's is under powering them. It's not so bad when you do that when you are just running the speakers as mid/highs. If you are going to run them full range you really need a bigger amp.

I would sell two of the 6x9's and all those amps. Get the right sized amps for the 6x9's and subs. Because four 6x9's and two 12" subs should bump in that boat with the right power. I can attest to the Apline amps being very easy on a battery as well.

Also look at getting a solar panel charger that you could lay on the deck while you are sitting. It would help.

tks for all the responses
all the amps are amps I already had here from horse trading at shop or getting when buds stepped up power
I did buy all the speakers

I can cut in the other 6x9s into the sides and not put low in the bench and really like to have the full storage there anyways
so I can buy an amp for the subs and still use the 400/4 on the 6x9s set in mid with subs bumping good
that would be a good start spot to see battery life

other route is did see alpine does have a 12" sub rated at 50-250rms
would they thump ok on the 400/4 bridged to 200 each
and use the other 400 for 4 6s

or would be better the polks on a bigger amp

If you use those subs IMHO you need a single channel sub amp that puts out at least 300 watts RMS. Run the voice coils in series, then both subs together in parallel that will give you a single 4 ohm load on one channel. Nightlife hit all the relevant points regarding the 6x9 placement and power.

I have operated a tunnel with 2 2.5's . The radio never came on the whole time we had that boat. Didnt sit much in it either . Pulled like a supercharged jet boat pinning the throttles at 5000 rpm though
i have horse traded and run almost the same stuff you have ,for cove jamming 4 properly installed 6x9 , 2 polks wired at 2 ohms each then feed at 1 ohm to a cheap hifonics or fosgate 1 ohm stable will work well to .
Check your bench and make sure it even has the ability to work as a enclosure , you may end up with a probox ported 10 under the cowl , those slam too.

this skinny hull with the dash moved back makes cockpit very small so lacks space for new style 7&8 rounds
so going to stay with the 6x9s mounted in the side panels beside bench as they will fit there
and go ahead and cut in 2 more beside bolsters in front
to keep them al high to stay out of the bench

as for subs 2 choices
stay with the polk subs and get a mono for them
with them wired series/parallel to keep at 2 ohm
the subs rated at 360 rms x2 for the dvc so will go with 700 mono
and use the 400/4 in mid setting for the 6x9s

or buy the alpines at 50-250 rms and use 2nd 400/4 bridged at 200

which route for subs for best sound

I run in a 33pp with 572s and dry exhaust with 6 6x9 and subs and can hear radio fine
the 3 os mercs at 16" centers really sings good but still quieter than the pp
just trying to get good sound while staying with smaller amp draw for the battery usage
I really like music playing while going across some snot with a little air,,,lol
putt this boat together for the under 30v runs and smaller snot air