Minimal custom flavor

Install Ubuntu server (barebones ,no packages during install).
Make sure you are connected to your dhcp during install.

sudo apt-get install xserver-xorg-core (window server)
sudo apt-get install xinit (initialization tool)
sudo apt-get install blackbox (window manager)
sudo apt-get install firefox (optional)

What is the point?
Whit this you get minimal GUI install that you can jump into and (equally important) exit.
Inside you can run firefox. Also this demonstrates flexibility of Linux.
(Don't bite my head off, I just figured all this out! yay! )
(Experiment with startx without window manager , see what happens :)

You may also consider: cvt, xrandr and adding 10-monitor.conf
(xrandr will only run inside x server)

One-up would be to do like I have and just start with stock Debian.

Or you know, ArchLinux.