Disk and File System Configuration?

[Gdal]

Hello,

I am currently using Proxmox v.7 on a Dell OptiPlex 3020 equipped with an Intel Core i3-4160 (Dual Core 3.6GHz 3MB w/HD4400 Graphics), upgraded to 16GB of RAM and a Kingston SSD UV500 960GB drive, to run a Home Assistant VM and a second one for Windows 11. I also have an old Synology NAS for photo storage.
I would like to set up a configuration to integrate the whole thing, keep a RAID to secure the DATA (in addition to external backups).

Mon usage:

• Home Assistant
• Windows 11
• Immich
• Network management, OpenSense?
• NAS for storing documents, photos, …, FreeNas?
• Pi-hole

The configuration I am considering:

• Processor: Intel Core i7-12700k, BX8071512700K, 3.6 GHz / 5.0 GHz, 12-Core (8 Performance-Cores + 4 Efficient-Cores), Intel UHD Graphics 770
• Motherboard: ASROCK, B760M-HDV/M.2, Micro ATX Socket 1700 Intel B760 Express, 2x DDR5, 2x M.2 PCIe, 4x SATA 6 Gbps ports, PCI-Express 4.0 16x, LAN 2.5 Gb
• Memory (minimum 32GB): CORSAIR, CMK64GX5M2A4800C40 , 2x 32GB DDR5 4800Mhz CL40
• Hard drive (minimum 2TB): WESTERN DIGITAL, SSD WD Red SA500 2TB, WDS200T2R0A, or SSD WD Red SA500 1TB, WDS100T1R0A
• Graphics card: None (CPU integrated graphics controller and CPU integrated graphics core compatible CM)
• Network card: QNAP, QXG-2G2T-I225, PCI-Express 2.5GbE 2-port card

Configuration:

• SYSTEM: 1 disk for the Proxmox OS? Size?
• VM, LXC: 2 x 1TB disks in RAID 1 with ZFS file system
• DATA: 2 x 2TB disks in RAID 1 with ZFS file system
• BACKUP: ?

I read a lot of page and I admit to being a little lost on the disk
What do you think? Or maybe there are other possible and better configurations?

Have a good day,