Diy dc blocker, net filter, auto on, soft start, ... solution using boards

Hi,

While looking for a dc blocker, I have a humming transfo, I started thinking about going all the way as I anyway wanted something to turn on and off my gear at once and boards seem cheap on aliexpress.

I have in total a pre amp, mini dsp, tv, 3 mono blocks and 3 subs connected, so 9 connections. I spread them over 2 different main fuses to spread the load. In total the wattage I estimate about 4000 watt, 230 volt.

I was thinking of building 2 boxes, 6 connections each so I have some extra, with a dc blocker and net filter in it, a manual switch to turn all on and off and an auto start, so when I turn on my tv the rest also turn on. When I switch all of I want it to all switch off.

Not sure if I need a soft start too as all my amps will be immediately on? Would I need other boards as well to "improve" my current? Protection from lightning? Cheaper to do it now instead of later.

Which boards would I need? I find it hard on ali express or ebay to find them using the search functions, let alone understand it. I think I need a 10 ampere minimum? Anybody built something similar?

Which metal or plastic case could I use? Would be nice if it looked good too.

Thanks!