Listing multiple authors in the sidebar, with bio and gravatar

I’m looking for a plugin that lists all the authors of a multiple author blog, with a gravatar, a feed icon and perhaps their bio. I’ve looked around and found only wp gravatar – which has a sidebar widget, but seems restricted to listing only one, pre-designated author – and list authors and list authors plus, neither of which support gravatars.

Am I searching in vain? Or does such a plugin exist? If not, does anybody have an idea of how I should go about doing this?

Thanks,
Iain