Box of scraps computer parts into plex server or? Help

Hi all, I recently upgraded my PC and as a result have the following spare parts that are not really moving on offer up. I am currently using an 8 year old broken screened laptop to run plex and access it remotely but the problem is that the space is running out to store linux iso's.

1. Am I better off getting like a mediasonic probox DAS to connect via usb3 to my currently running laptop with 4 separate 8tb HDDs or do I
2. Use my existing scraps- 3700x CPU (gammaxx 400 cpu cooler) ,750watt psu, and 1660ti GPU to build a whole other server to run plex. I know if i go this route I would also need to buy a motherboard (probably go cheap secondhand am4?) I would also get a cheap PC case. I would also get some cheap ram on offer up, sometimes they come with the mobo if I am lucky. Probably 16gb since most available is 2x8. Also do I even need the gpu (1660ti) to run plex?

Thank you for the advice!