Plex PC Recommendation Keep Current, Rebuild Old or Purchase New

I recently started using plex/radarr/sonarr/nzb360 and trying to get everything automated since I’m home for corona. Currently in medical school so I don’t plan on being home for long periods for the next 8 years or so and wanted to this up to automate and be as stable as possible. I currently have about 10 remote users with up to 5 at one time. I’m presently using my main desktop but I have an old PC lying around that I was planning on using instead while purchasing a few components. I’ve been lurking on these forums and saw that a solid performing spec could be had for cheap so maybe buying a new setup would be better. So my question is do I keep my current desktop, use the old one or buy a new setup.

Old PC

  • i5-2500k
  • Gigabyte GTX 650 - 2 GB | GV-N650OC-2GI
  • 4x2GB DDR3-1600 PC3-12800
  • NZXT Phantom Case
  • MSI P67AGD65 motherboard
  • 2x1TB HDD
  • 1x250GB SSD

Current PC (HP 580-023w)

  • i5-7400
  • NVIDIA GTX 1060 3GB
  • 2x8GB DDR4-2400 PC4-19200
  • Odense2-K motherboard
  • 1x1TB HDD
  • 1x250GB SSD

Currently all media is on a 8TB external HDD with plans to purchase more HDD and possibly shucking.

Only planning to run Plex, Radarr, Sonarr, Torrent 24/7/365 with windows 10. Limited/No transcoding since my internet is 230/10 mbps so I’ll be direct streaming most of the time. Thanks in advance for any suggestions.