As part of the Model Engineers Digital Woirkshop range of products I am supplying per-configured ITX based computers with a fully licenced copy of Mach3 already installed. These are configured for either the MicroMill Taig controller, or the C11 breakot board, and can be configured for any other target controller as required.
http://medw.co.uk/wiki/?page=Mach-in-a-box

Slowly getting to a complete packaged system
http://medw.co.uk/articles/read.php?article_id=12