I had a friend do the setup for me on a new VPS running Ubuntu 10.04. I've attached his instructions (INSTALL.txt) and copies of the relative config files.
So we're running nginx, with squid functioning as a reverse proxy. (Fun!). Moodle is mostly working okay, though I am having a few issues with attached files at the moment.
As I said, I had someone else set this up and leave me semi-complete instructions, so hopefully they're thorough but their might be a step or two where you have to improvise. Also, I'm not sure which parts of the config files were changed and which were largely the same as before, but I guess just compare them to what you've got and add in what's missing.
Or if you get stuck, you could hire him to do it for you :P
Hope this helps! (And sorry I don't have more complete instructions)