To be honest I took part 1 exam as an oppurtunity
to read books about b2b integration, art of middle ware and couple of more books. More than my score I feel that I gained a lot of knowledge out of this. I don't think you need a lot of experience as a J2ee developer for this exam though I have 3.5 yrs of experience as a J2ee server side developer. But development experience will be always handy in real life as a technical architect is considered as a MVP in the Industry. Why I am saying this the way I looked at things as an developer has changed totally from the perspective of an Architect. I read the following books
Ejb 1.1 specification from Sun(It is crystal and clear like Bhagavad Gita ,you don't need any other book)
UML distilled by Martin Fowler(I took this
exam as a chance to get to know all the symbols though exam questions are really easy)
Mark cade on SCEA( This book is enough for protocols, security, Internationalization, Design pattern. Common Architecture is also good in this book but you need some more materials)
Mastering Ejb by ED Roman(free download from serverside.com). THough I didn't use this book for sufficient I used this book for several topics like JMS tutorial, Design strategies, and tutorials on several topics are available on the Appendix
Whizlabs Mocks and mock exams that are free and several articles that are available on the web. I have made good use of my Cable Modem Connection very well.
A small suggestion is that don't just prepare from the exam point of view only, take this oppurtunity to expand your knowledge.
Good Luck