Help on best array/cache setup

Hi all,

I'm new to unraid - until this week I was running a linux server using raid 5 but I am now moving to unraid. I'm looking for a bit of advice on how to setup the array/pools and also on PCIe -> NVME adapter cards.

I have a motherboard with 6 x 6 GB/s SATA ports, 1 M.2 Slot and I also have a spare PCIe 3.0x1 slot. (MSI B560M A PRO motherboard with an 10th Gen i3 in case that matters)

Disk wise I currently have 2x6TB WD RED, 2 or 3 x 4TB WD RED (one has a damaged SATA port and I'm not sure it'll survive being moved to the unraid case) and 1 x 120 GB SSD. I'm currently using about 7TB (i.e. the existing 2 WD REDs are close to full)

What I want is a parity protected data array and also all the UNRAID Dockers/VMS to be protected and fast. 

I've watched SpaceInvader1's video here: https://www.youtube.com/watch?v=jgRSr7yBZfs which is good but he doesn't protect his VM/Docker disks. Also he splits docker and VM on to different caches and I'm wondering if that is strictly necessary?

So I'm thinking of a couple of ideas. 

1) Add all 5 Mechanical drives into an array. Add the 120 GB SSD to the last SATA port and use it as a cache. Buy 2 x NVMe disk and a PCIe to NVME adapter card and then uses those for a mirrored cache for VMS/Docker

2) Add all 5 Mechanical drives into an array, leave one SATA port free for a future mechanical drive. Buy 3 x NVMe disk and a dual PCIe to NVME adapter card (e.g. this one: https://www.amazon.co.uk/gp/product/B09H7JPNDQ/ref=ox_sc_act_title_2?smid=A2KREUBK79VF64&th=1) then I'd have 2 of the NVMe disks mirrored for VMS/Docker and the other as a cache drive. If I did this do I need to worry about the location of the NVMe i.e. plugged into the motherboard or the adapter card? I assume I'd be best putting one mirrored drive on the motherboard and the other on the adapter card?

3) An option similar to SpaceInvader1s where I have the Docker and VM pools separate but to do this I'm going to need 5 fast disks (2 for VM mirror, 2 for Docker mirror and 1 for cache) which I think will have to use 2 of the SATA ports and then I'd only have 4 SATA ports for my date array. Is it worth considering this?

Any help much appreciated.