Yes, they are a complete setup, very similar to yours I think (ballscrew between 2 linear rails with 4 carriages). They have a lid and two belts that keep dust debris out of the innards. I have had them for awhile, but only recently found a suitable drive for their 300 watt 4 pole brushless motors (4 pole brushless motors run horrible on trapezoidal amps). Just a few minutes ago I was doing some load testing on them, moving a car battery around at 800IPM (the only heavy thing I had nearby
I am planning my router/mill similar to yours I think. One slide will move the table and the other slide will be mounted to a fixed ganty (with z mounted to it). For general wood/plastic routing, it should be fine to cut anywhere on the 20" x 20" 1/2" thick mic6 cast aluminum plate I plan to use for the table. When I want to cut metal, I will just stick to the center 8"x8" section of the table which is fully supported by the slide's 4 bearings underneath. Best of both worlds! :-)