The multiple choice exam for SCEA is based on J2EE 1.2 so need to know EJB 1.1. You need to know the basics of JMS but no in depth knowledge (therefore version is irrelvant). If you know JMS is asynchronous then you basically prepared for that area of the exam. JCA is not covered as this was added in J2EE 1.3.
The SCEA exam tries to prepare you for being an architect. In this sense, you are expected to know the purpose of specific J2EE technologies and how they are used. Specifically, you are NOT expected to demonstrate development skills. You do not need to know the API specification or method signatures (compared to say, the SUN Programmer exam). regards, paul.