fucking hell, cross thread links don't work from 4chan to 4channel anymore?>first of all, do yourself a favor and nuke gnome-terminal
the anon uses urxvt as terminal, in arch it's rxvt-unicode iirc
it looks ugly at first but you can easily do whatever you want with it.
the WM is i3-gaps, a fork of i3, one of the best documented tiling window manager out there and a good start.
the statusbar is Polybar, i3 comes with it's own one but Polybar can do much more than just display statics, it's also easy to customize and very well documented.
the file manager is Ranger, if you are familiar with Vim it's very intuitive, if not, get familiar with vim, you'll have a lot of dotfiles to configure and vim makes things so much easier.
the browser is Firefox and for 4chan he uses 4chanX if i guess, maybe it's just a custom 4chan css.
pic related, it's the one anon asked for