Rob,
Many vacuum systems aren't complicated at all.Have you looked at some of the options for building your own on the Shopbot Wiki?
http://shopbotwiki.com/index.php?search=vacuum&go=Go
This is a collection of previous Forum articles regarding the construction, and use of vacuum hold down systems.
Some people have made a vacuum hold down using ONE piece of Corian...
"Share your knowledge. It is a way to achieve immortality"...The Dalai Lama
"Nothing is really work unless you would rather be doing something else....." Sir James Barrie