I have installed Openbox on top of Gnome version, then requested a package for openbox-menu, then added my usual config files (which I also provided for others) into Sabayon, then changed some entries from the menu.xml file to get "sulfur" as a shortcut to Sulfur instead of synaptic. Now Openbox is also compiled with the imlib2 flag, and with openbox-menu, with the relevant configuration files, here is what it looks like:
a pic of my desktop with Gnome Sabayon with Openbox on top (chose Openbox alone as a session):
I also use tint2, that I had to reconfigure a little, so to be able to right-click on it, to get the dynamic right-click menu also on it.
Here more infos about openbox-menu:http://mimasgpc.free.fr/openbox-menu_en.html
and if you wish to get my config files, I'll provide them with pleasure. Just say and you will have them.
I use feh to manage the background (command line all ready in the autostart file provided for the openbox configurations) and it is also possible to get it managed by pcmanfm.
Of course, you can use these config files as a base, reconfigure them to suit your needs. Basically the intention is to help people have an easy start. (They were done based on the personal ones from several people, and are available in 3 languages).
And... what else ? You can reconfigure the keyboard shortcuts at will. (There is good doc on the openbox wiki for that).
Of course, the gayake terminal being in Gnome is still available with Openbox on top of Gnome.
I must say I am very happy that the requests I have brought to the bug place have been taken in consideration so fast. It is a great pleasure for me to discover this distribution and it's community.