Best way to connect WS420

[Capta1n]

Here is what I have currently
Clarion APA4204 driving 4 in boats and a 4 ohm 300W sub
Clarion APX 200.2M driving Kicker 6500.2 on the tower
Clarion XMD 3 with two remotes
Cadence CEQ770 preamp equalizer
Mil-BTREC Bluetooth Dongle.

I don’t really want to replace anything as I have ballast and vinyl projects to do also, I am going to replace the Cadence as the pots are scratchy with a WS420.
I don’t really need the XMD3 apart from I like the remotes and i don't have room at the helm for the WS420.
My questions are;
What is the best way to connect all this together, currently every time I turn on the batteries I have to go through a set up of LPF 50, LPF 80 etc until I get to “rear” and then I get sound and secondly should I add another amp for just the sub?

I cannot tell how it is connected currently as it looks like this. If i am going to rip it all apart to install the 420 I want to make sure I get the most out of what I have for one more season.

I added pictures of the boats as i know you guys like pictures.

Neat Installation NOT.jpg

20150620_151532646_iOS.jpg

2014-09-21 17.50.23.jpg

[chpthril]

You really need to locate the Ws420 at the helm as that's what its for.

Yes remove the other EQ

Use the head units full range front rca outputs to the 420 or no input if you won't be using tuner and CD.

No need for another amp for the sub with the addition of the 420. Sub outputs on the 420 will go to the amp inputs for the chnls that the sub is on

[chpthril]

You really need to locate the Ws420 at the helm as that's what its for.

Yes remove the other EQ

Use the head units full range front rca outputs to the 420 or no input if you won't be using tuner and CD.

No need for another amp for the sub with the addition of the 420. Sub outputs on the 420 will go to the amp inputs for the chnls that the sub is on

[Capta1n]

Thanks Chpthril
I assume by using the front RCA's i won't need to go through the setup each time i power up.

I'm OK with the 420 not being at the helm as the wife normally drives the boat and i drive the sounds.

[chpthril]

Correct, the front rca output should not need to be reset after turning off/on battery switch. One set of rca into the EQ main, one set out to tower amp, one set out to the half of the 4 chnl driving in-boats and sub outputs out to half of 4 chnl driving sub

[Capta1n]

Thanks Chpthril, switched the RCA around with existing Eq and it works much better now. I will try and figure a way to relocate that when i switch it out for the 420.
Thanks again for the help.