I am extremely happy with a Mac Mini that dual boots Ubuntu and has a couple 22" LCDs. It's small and gets out of the way, works with all the accessories I had laying around, and is well under $1k with the monitors ~$120 each. Figuring out ReFit was a bit of a pain, but it was a one time thing and now it runs beautifully.

Judging from your "pip install ..." bit, you're doing Python work. I do Python backend web development and the Mac Mini (2009 at that) has never let me down.