My company recently switched out all of it's older Dell for newer ones that are capable of running Win11 (because existence is pain). As a result, I now have three Dell micro PCs two of which are on DDR4, one is DDR3. All of which cost me nothing.

I've already put Proxmox and OpenWRT on one and shitcanned the crappy Linksys my ISP gave me, and am about to put another into service as my home server. The third one has yet to reveal its use to me, but it'll come.

I currently have eight computers of various specs, sizes and configurations, and am happy to rehouse a bunch more.

You want a business laptop. Most of them are designed to be repairable and have parts readily available. They are also a lot more durable than the junk you find in the stores. The only downside is they are not good for gaming, but you can always pick one with Thunderbolt/USB 4 and use an eGPU. Just make sure the port has all 4 PCIe lanes connected.