Finally done!!!! WOW! what a difference. My wife even thinks it was worth it.
here we go:
first start out with overall diagram of what I did.

Next here is the subwoofer location. Notice that the sub enclosure fit perfectly under the passenger seat. Still allows for full movement of the seat from forward postion to back facing position.

I wanted to fill out the back cabin area with sound. the stock boat did not have any speakers back here and as you can see, do to the trim, I could not easily fit another set of speakers in the back.

So I ended up putting a pair of 4" polks next to the cooler. not very loud, but it fills the space with amazing sound.

My boat did not have swim platform speakers originally. so I added the a pair of Polk mm651um. They are set up on a separate zone. Tested this weekend by cranking up the swim platform for a tuber, they could hear it great and I had normal sound in the boat.
Swim platform:


I replaced the sony swim platform remote with the Alpine. It can control either zone.

Ok, now onto the replacement of the existing speakers. I replaced all 4 with the Polk mm651um's. Huge upgrade in sound.
Pics of the front bow speakers behind the stock speaker cloth. ( a couple of different angles)


Here is a pic of the speaker in the cockpit area with grille removed.

And here it is with the grille on

Powering the speakers, I installed a couple of Alpine Amps. I located them in front of the steering console, where I store the bow filler cushions. Plenty of room for both. They use the 2 stock amp fuse connections back by my battery switch.

The heart of the new system is my receiver. This head unit is Fantastic! allows for dual zones, very expandable, easy to navigate, and looks cool!

Since the receiver has a "true" ipod connection, I decided to add a built in usb socket (clarion accessory) in the cubby hole next to the stock Aux jack (hook that up to the head unit too) and 12v adaptor. Makes everything look like that it came from the factory configured that way.

Here is a pic from a different angle of the dash and cubby hole. Notice my ipod is connected and fits nice in the bin.

I hope that you find this helpful in your upgrades. I pained over the planning for this, worried that I would screw up my new baby. It paid off! This is the type of system that Four Winns should have installed in these boats from day 1.
Thinking of adding the phone bluetooth feature to the system next. Then again, I do not know if I want someone to disturb my music out on the water.