@Sirs0ri np.
I can recommend the "upcycling" & "reuse" route given #ThinClients offer decent performance for a mini server and more often than not are completely fanless, making them excellent at home.
- I do use an #hp t620 for that myself, and unlike the #ProBook|s it seems hp didn't do #DRM with the #RAM on their #ThinClient|s...
It's not that I don't say any other brand is bad, but those brands have been reliable to me and are known to use reliable & new components and not new-old-stock or "upcycled" chips ripped from older machines and sticks.
- And since you ain't looking for some "vintage" SD-RAM there's no need to dive into those.