Check with your local automotive paint shop. They should be able to mix you up any color in any kind of finish you want.
As to how they do it, it's a matter of adding the proper amount of flattener to the paint. Most of the systems I've seen don't use a clear for flat or satin paints.
You may want to check the Hot Rod Flatz site directly, as i do beleive they have satin finish paints, too. I also saw a satin paint being used on a project truck (Knucklebuster) on Gearz. Give me bit, and I'll see if one of they guys over there knows what brand it was.

Bill Burmeister