You can use seam-gen as a base, but you will need to edit the ant script manually to make it multi war. If you are using jboss tools to build your project I am not sure how you would do it.
Make sure you are using 2.2.0.GA. This is the only recent version of seam that works properly with multi war projects. You also should be aware of JBSEAM3849, which is a bug with the hot deploy filter in multi-war projects.
Thanks Stuart Douglas
Now I'm using the 2.2.0.GA, but
¿Can you give me an example of how edit the ant script manually?; beacuse I don't know how to do it exactly