My reply to him for the moment:
I posted up your email in the moderator's forum. I'm honestly not around often enough to know what we need in terms of mod staffing at the moment -if nothing else, though, this'll get your name on the list for the next time we go looking.
Typically the process is a bit of a popularity contest, to be honest. When I was made a mod, the then-mods looked at the various users who had a presence on the forum, debated pros and cons of each for a bit, and then voted.
If there's a reply to my thread on the mod forum, I'll let you know.