You can also get a lot of the parts you need from McMaster.
Here is a flatbed table we built out of a cannibalized diage laminator and sign extrusions.
Never finished it with the pneumatics cause it worked so great as is.
The gantry has 4 heavy duty bearings on each side it moves like butter and it laminates 4x8s flawlessly.
The springs provide the tension and if I need to raise the roller it pivots on an axle.
I believe if your doing one offs a rig like this is the only way to go.
In the mean time you could always get yourself a big squeegee from Dale.
It's a great tool to have for others applications.
Good luck on your table.Once you get it going you will wonder how you survived without it.