I have a Black&Gold EX-21.
http://www.seyco.com/It came with a dust collector connection. It is a thin, clear plastic piece that sits under the blade hole. They also drilled a ring of holes in the table around the main blade hole (see the picture). The plastic piece is glued to the underside of the table and is flat. It feels like the table was milled out about 1/8" or 3/16" under the plastic to allow dust to flow to a vacuum connection. The vacuum connection is 2 1/2" and is attached to the table with 3 screws with holes tapped into the table. If you contact Seyco, they probably have that as an option.
I'm not thrilled with this arrangement. Small parts that fall out of fretwork or portrait work get stuck on the plastic piece or btwn the plastic and tabletop.
I have a Stanley vacuum (1.25") that I use on it so I had to adapt to the 2.5" hole. There are no adapters to go from a 2.5" fixture to a 1.25" vacuum (although there are adapters to go the other way) so I cut one with the EX-21 from a piece of 1" pine. You can look for that posting, I think back in Feb.