I am currently using DVD Flick  in Windows to author a DVD from a .vob video file in a manual process, i.e. setting up the project etc..
Now, I would like to
If possible the solution should allow to create an ISO for easy duplication.
Does anybody know any software that supports this?
dvdauthor  is an excellent command-line utility that can do what you want. There are also a number of GUI authoring tools, a lot of which are front-ends for dvdauthor:
On Ubuntu, some of these are already included in the repository, so you can install them using apt-get or graphically through the Add/Remove.. menu.
A full list of front-ends to dvdauthor, as well tutorials on its use, are on the project site. http://dvdauthor.sourceforge.net/
This page offers a command-line solution:
You could encapsulate those commands in a script, but you might have to include some options for things like aspect ratio.