Comment by IgorPartola

For me it was important to have ECC RAM and laptops pretty much never have that. My personal recommendation is an old IBM/Lenovo workstation tower as the base. I bought one for $35 on eBay and added $40 of RAM (32GB). A $10 UPS from Goodwill with a $25 battery from Amazon, and whatever hard drives you want. I run Ubuntu and ZFS on it but next time would probably opt for FreeBSD for a nicer OS.