Build recommendations for a jack-of-all-trades systems

[devemia]

For context, I have been in IT for a while and am a long-time TrueNAS content viewer (Lv1tech, Lawrence, Reddit, etc.). That said, I have never built nor used one myself, so I decided to jump into this DIY rabbit hole as a hobby project (100% noob here). Below is my intended configuration and my rationale behind them.

• CPU: Ryzen 5600G - No ECC, not a critical NAS and I don't want to spend too much on that. I also don't want to spend time hunting for used DC components.
• RAM: 64 GB DDR4 - Already owned, no ECC.
• MB: 2x NVME, 8x SATA 6GB/s - cheap and great storage configuration, also no ECC support.
• SSD: 2 TB x4 - Already owned, cheapest and lowest tier SSD, unknown TBW, but it is 1200 TBW based on some comments. If they die, so be it.
• Cache/OS: 3x Intel Optane P1600x 118 GB - Already owned, two can use the NVME slots, for caching. The other is for OS installation using PCIE to NVME adapter.
• Network: 10 Gb/s.

I don't have any specific use case, or any critical data to store. This system is practically a playground in a foreseeable future! Eventually, it will store my data (non-critical), maybe host some VMs, and is a hub for local streaming.

With that said, I have 4 spare SATA slots, what should I buy next? Here are some potential options.

• 2 TB x 4 (or more) NAS-rated HDD. These will be in different pools and contains replicas of the SSD pool. Both pools have RAID Z1.
• 2 TB x 2 SSD (garbage tier), and 8 TB x2 x NAS-rated HDD. The SSD pool will be in either RAID Z2 or Z3 (so 6-8 TB of usable storage), hence I use 8 TB HDDs in another pool for some flexibility in configurations.
• 4x SSD (also garbage tier). Maybe 2 pools (4 and 4), or 1 pool with a VDEV of 8? RAID Z2 or Z3.

Any suggestion is greatly appreciated!