The only way to create a JSR-181 service for Petals, is to create a Java project, implement a JSR-181 service, package it as a JAR, and then create a new SU project that will import this JAR.
The studio should provide a single wizard for all of this.
It should let the user choose between creating a new JSR-181 implementation (implementation first) or create an implementation from an existing WSDL. The SU export should package the Java implementation in a JAR file on the fly. And it should also enforce the coherence between the WSDL, the jbi.xml and the @WebService annotated classes.