Re-build a DS1817plus with 8GB Ram installed

[Enquiries]

Hi,

Many complemets for your video's & information provided on YouTube.

For that reason I'm now re-building my "old" Synology DS1817+ with : (1x 1TB & 1x2TB & 1x 3TB & 4x 4TB & 1x 8TB)
Into a "new" NAS system using the following: components (4x 4TB & 4x 8TB):

My 8GB RAM upgrade is into 16GB with a SeQuell set of 16 GB kit (2 x 8 GB) (PC3L-12800S) RAM
(According Amazon suitable for Synology NAS DS1817+ and thus purchased).

Considering for additional "fast" storage or caching?:
2x M.2 SATA 600 SSD - WD Blue SA510 1TB's
or
2x M.2 NVMe SSD - Samsung 980 (PRO) or WD Black SN850X - 1TB's

Raid type will be SHR and my question(s) are:
- Should I consider additional fast storage or caching?
- Which sequence of HD capacity should I apply in this unit first?
4x 4TB and later the additional 4x 8TB or
4x 8TB and later the additional 4x 4TB or all-in once
4x 4TB & 4x 8TB (which has my preference)

Many thanks for any reply from your side

Kind regards,
Fred Oprel