Boat amp/speaker install

I put in a new head unit (Kenwood Marine Bluetooth Stereo KMR-M312BT) last year with 4 new kicker speakers (Kicker Marine Boat 6.5" 4-Ohm Waterproof Speakers White- 41KM604W). All good here.
I am adding a 4 channel amp, a subwoofer, and 4 wakeboard tower speakers (Kicker - CS65 6.5" 100w Coaxial Speakers 4-Ohm) to the setup this year and need some help to know how to wire this.

The amp is a Kenwood M3004 4 channel amp 400 watts
Also need some help in knowing what concerns I should have in finding a place for the amp? Is heat an issue? Can I just mount it in the storage spot in front of the driver on the carpet?

I have a 2008 21ft Bayliner bowrider

so 8 speakers, a sub on a single 4 channel?
Biggest issue is making sure the amp doesn't get wet and then the long run of power and ground wire to the battery. Running the wire for the towers can be a pain on some boats.

My only concern with what you have said would be power for all of the speakers on what you have said.

DO you think a 6 channel or 8 channel would be more prudent?
Would it be best to mount it back near the battery?
Or mount it up near the head unit?
Thanks for your help.
Kind of a novice at this but want to learn.

Get another 4 channel. Run the 6.5's on one, bridge the other for your subs. That's too much for the amp you've got.

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Pegleg Charlie
Builder-Charlie Cannon Subwoofer Enclosures and general troublemaker at
LMMFAO Corp.(LOL)