The preposition of always up to date would be great if that wouldn't mean that your PC doesn't work properly most of the time due to some new bug or incompatibility.
We've run Arch on embedded PCs (arm) due to out of the box docker support, but after updating a year later we've literally were unable to deploy Docker containers. There was a bug in the kernel, and no amount of hacking, upgrading or downgrading made it work.
Luckily we had a sdcard snapshot a year old.
I suggest Ubuntu or Debian, they got good docs, good support and generally a positive community.
As far as windows managers go - pick what you like. Gnome looks slick, xbuntu is my go-to for Chromebooks and default isn't too bad.
A lot of devs in our company go for tiling desktop managers - i3, awm....