I would switch to the Mac Pro, even an older tower one. They still have bonkers performance (it's my main development machine for native C++ and Windows development in a VM). But you don't feel like you're fighting with the system to do "unix" things like you do on Windows, and it doesn't feel like you're trying to fit a peg into a square hole, which shoving all GNU tools etc. onto Windows certainly feels like to me.

Or I suppose you could go with Linux and fight the shifting desktop sands? (That's why I got fed up with it and switched mainly to Mac OSX; despite the OSX changes, they're gradual and not insisting that we drop the dock or window behaviour etc.)