Advice on 4k setup

This software looks great, and a friend mentioned it, which as a geek, soon had me going down the proverbial rabbit hole. I think I kind of have everything straight in my head, but would be grateful for any advice, thoughts or corrections based on the below.

I currently have a mix of 4K and 1080p sources

Khadas Vim running the latest version of LibreELEC (4K)
PS4 (Standard - but upgrade to PS4 Pro possible in the future)
Xbox360 (Rarely used)

going to my AVR which is a

Yamaha RX-V383 (which is HDCP 2.2 compliant),

which then outputs to a

Hisense 50" AE6100 (Fabulous value for money in case anyone is wondering.) I don't actually use the TV really as anything other than a dumb monitor, occasionally use the TV for catchup services and I understand that any Hyperion setup will not work for these.

My current thought process, is by taking the output from the AVR and splitting it, I could feed it into Hyperion, making it work for all AVR sources.

From my reading I think I have this straight, so would appreciate having an experienced eye look over this.

Step 1. HDMI out from AVR. The easy bit....

Step 2. Wondering about this bit. If I get a splitter capable of outputting 4K on one output and 1080p on another such as this Clearvision HDMI Splitter with Scaler 18Gbps HDR 4k 1in-2out or whether it's better to get a dedicated 4k splitter, outputting 4k on both outputs such as this Clearvision HDMI Pro Splitter 18Gbps 4k 1in-2out and then feed that signal into a 4K to 1080p converter?

Step 3. (Only if I go with a dual 4K output splitter) HDMI to AV Convertor such as this

Step 4. RCA to USB Convertor, from my reading and specifically this thread, there are two options, one is based on the UTV007 chipset so something like this , or something based on the STK1160 chipset such as this stick. It seems reading this thread that the UTV007 chipset is preferred, is that still the case?

Step 5. Raspberry Pi running Raspbian is my preference, but happy to take advice on this.

Step 6. Arduino? Not too sure whether this is necessary or just recommended, thoughts would be appreciated.

Step 7. LED strip WS2801 based on the information I read here.

Pretty sure that covers as far as I've got in the thought process thus far.

Like I say I'd be really grateful for any pointers or comments.

One thing I forgot to mention, is I'd like to preserve CEC if possible through the splitter. So any advice on HDMI 4K splitters is most gracefully received.