This one is what I use in my 'desktop' [Fractal case] Plex server since 2020:

amazon.com/gp/product/B0085FT2JC/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

You'll use these cables:

https://www.amazon.com/gp/product/B012BPLYJC/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Look up fan mod for the card, I used this little boi:

https://www.amazon.com/gp/product/B009NQLT0M/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

It's basically plug and play. The fan "modification" isn't too hard. The card is considerably cheaper now than it was in 2020. My server is completely stuffed with something like 9 drives and 3 SSDs plus a GPU so the fan mod was to keep the temps 'reasonable' in my stuffed case.

Thanks, this reply is very helpful. I now fully understand all the terminology (I was misusing terms). I have initiated a return of the PCIE card with 4 SATA ports, and I have ordered an LSI SAS "8i" card. I torrent lots of movies, and would like to start being able to always download the best quality movie. So I probably won't ever have the need to go beyond 8 additional drives. I will have created a dedicated server by that point. I bought this card last night: https://www.amazon.com/gp/product/B0085FT2JC/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

Thank you for the ebay suggestion; I will bookmark it.