Can I download Ubuntu 'Lite' - just the core?

As a bit of a personal project im wanting to create a very lightweight desktop environment with something like fluxbox.

As a start point im wanting to use something like a lightweight version of ubuntu - Ubuntu but without the gui and only the most limited set o f applications, and then move from there. Is there anywhere i get something like this?

Or alternatively am i best just to download Debian and then add the ubuntu repositories to the sources list so i can still the best bits of ubuntu software?

** Edit **

To clear up any confusion - im looking for minimal install that contains only the bare minimum ubuntu needs to operate as a distinct distribution. I.e as few applications and auxiliary libraries as possible. From there i want to add these manually myself.

I am aware that you could argue that the applications and libraries are what make ubuntu ubuntu - to an extent i agree. What i want to do is make use of the ubuntu infrastructure and repositories, whilst still coming up with something of my own creation.

Ubuntu Minimal CD here: https://help.ubuntu.com/community/Installation/MinimalCD

See: http://www.psychocats.net/ubuntu/minimal (icewm) and: http://wiki.dennyhalim.com/ubuntu-minimal-desktop (fluxbox) (his one line "quickstart" is good)

Ubuntu Repositories in Debian will create problems, if they will load at all!!!

For minimum Debian look at: http://auriza.site40.net/notes/debian/xfce-minimal-installation/ (obviously xfce) and: http://stray-notes.blogspot.com/2010/11/debian-minimal-install-xfce4.html (also xfce)

How about Ubuntu Server? No desktop environment. There's no real difference desktop and server Ubuntu other than the default packages. The "server" packages (apache, bind etc) are optional installs in server.

If instead of Fluxbox you could go with XFCE, there's Xubuntu. There was a Fluxbuntu but it seems to have faded away.

There is also Ubuntu Core for those looking for an extremely minimal Ubuntu environment, even smaller than Ubuntu Minimal. This is intended for embedded devices such as in-vehicle infotainment systems, television set-top boxes, etc. It is a very minimal kernel and userspace intended for use as a development platform. It is not suitable on its own as a desktop or general purpose server operating system.

Ubuntu Core is supported on x86 as well as ARM systems.

Information about Ubuntu Core is available on the Ubuntu Wiki here: https://wiki.ubuntu.com/Core