So, I see one possible way to approach this.
Perhaps we could facilitate funding an Outreachy intern for Design & UX for the Sustain brand and web services. I think @riecatnor is modeling what this could look like with a fully design-focused Outreachy internship.
I’m not sure what budget is available for this and how funding would work, but we could probably build up a coalition of inter-organization mentors for this project, if funding is not a hard blocker. Outreachy interns are approximately $5500 USD for one intern in an Outreachy round.
Thanks for mentioning these sites! 
I am wondering, is it too early to reach out? I feel like I am still framing this idea in my head. I think cross-posting is a great idea and I’m happy to do that work. But I’m wondering when is the most constructive time to invite more feedback. I trust your judgment more than mine since I am not deeply familiar with either community!