Funny, I was searching this same topic yesterday and couldn't find much good info. I am in the process of doing it right now - I just did a full repaint and the handles now look out of place since they are all scratched up.
The shop took them apart, and is doing a gloss black powerdcoat with clear over on the top. I don't know how they will turn out yet, but if it's good, then we might offer up the service to the community. I'll let you know how it goes!
Some threads refer to them as being plastic, but I'm told they are actually aluminum.
-Josh