What is it about the .zip version of JBoss 4.0.5 that doesn't allow Seam to run on it? I'm evaluating NGASI AppServer Manager. They have JBoss AS 4.0.5 support, by way of an automated download, but I'm guessing that it's the zip version.
I think the easiest way is to install 4.0.5 with EJB3 support from the GUI installer once on one box. Then, you can copy the installation directory to any other computer via an automated script.