JBoss AS has tomcat integrated. You don't need tomcat if you want to use JBoss AS.
Tomcat is only a java 'web' container. JBoss is a fully java application server. So based on you needs you should choose between both. You can't say that one of them is the best because then you would compare apples with peares.
If I where you then I would first read some stuff about jboss and tomcat. At first it is complicated but you need some basic knowlage about that stuff before you start developing java webapplication.
well - I had this sense that tomcat should be inside JBoss - but I didn't found any directory named 'tomcat' or 'catilina' inside JBoss installation. So - to what should I point when I am required to provide tomcat path in seam example applcations build.properties file?
And what about web-console? Is it is coming only with non-web-installation or with non-EJB3 configured JBoss? Can I get it and add to JBoss separately (e.g. deply as additional application)?
For the seam examples set your jboss.home to the directory of where you installed jboss too, for me it is:
jboss.home = /usr/local/jboss
Tomcat is located at: