JBoss Central doesn't propose the Wildfly archetypes when a Wildfly runtime is selected, even though they have been released in Maven Central : http://search.maven.org/#search%7Cga%7C1%7Cg%3A%22org.wildfly.archetype%22

They should be added to stacks.yaml, with environment: web-ee7 for the pure webapp and environment: full-ee7 for the EAR