Those things are ancient. I had pretty much the same model 10+ years ago.
Personally I've had good luck with the https://www.amazon.com/iStarUSA-Group-3x5-25-Trayless-BPN-DE350SS-BLACK/dp/B008RRZI14. Tool-less, SAS/SATA, better airflow and you can find it on sale for $40-50.
Yes, those are called DAS's (direct attached storage). Something like this? They are RAID capable but it's not required. You would connect it directly to the Shield rather than over the network.
I put three of these in the Rosewill chassis and they worked perfectly.
I use these and love them: iStarUSA BPN-DE350SS-BLACK 3x5.25 to 5x3.5 Trayless Black https://www.amazon.com/dp/B008RRZI14/ref=cm_sw_r_cp_apa_Em6GybXVHN0GW
They're still SATA though
I don't know how many free 5.25 bays you have but these work great iStarUSA BPN-DE350SS-BLACK 3x5.25 to 5x3.5 Trayless Black https://www.amazon.com/dp/B008RRZI14/ref=cm_sw_r_cp_apa_xoSCyb2ESWDZV
You're looking for a DAS (direct attached storage). I found this on Amazon, but there are many many different options. DAS's are attached directly via USB or eSATA, whereas NAS's use ethernet and can be accessed over the entire network. NAS's are usually more expensive because they also act as a servers and house a CPU, RAM, RAID controller, etc.