For decades, determining how to teach computing ethics effectively to undergraduate students has been a major concern. As more universities integrate computing ethics into their curriculum, or seek to further refine existing content, who is involved in teaching computing ethics has come to include both graduate and undergraduate teaching assistants (TAs). However, the role of TAs in ethics education is not well-understood, nor are the responsibilities, challenges, and support needs that might distinguish Computing Ethics TAs (CETAs) from their peers in technical computing courses. This paper addresses this gap in two ways, drawing on qualitative and design research methods. First, by interviewing CETAs and their supervising faculty at two universities, we identified common motivations, struggles, and goals among CETAs. Second, drawing on this data, we developed and piloted a cross-institutional support network for CETAs on the messaging platform Discord. Despite challenges in the deployment of the server, our results indicate that cross-institutional online communities have the potential to assist CETAs in professional development, in expanding perspectives, and in strategies for dealing with difficult topics. Furthermore, our platform can be retooled for future use within and between computing ethics courses. We hope that our research will contribute to fostering community and support for CETAs as part of improving computing ethics curriculum writ large.