>>53708528
a laptop

>>53708528
workstation laptop or mini itx build

Laptop with Thunderbolt 3 (like the Dell XPS 13) and an eGPU.
That way you only bring the power when you actually need it. Or you just go home/to work when you need it.

Buying a w520

prob a laptop
you could check out thin clients but they're really weak
if you want to be a dork you could get a 1U server chassis. The fans are loud AF though