Richard the Woodpecker offering seems attractive. But the use of only UHMW tape on the sliding surfaces is a less than elegant solution to the friction problems. It works but I I have never been impressed with the longevity of the tape.
In addition the set size of the extrusions make the set not particularly adjustable. If you notice in the Malecki video, he's got the rails sitting on strips of what appears to be MDF to get the height he needs. For a thinner piece you'd need to put a riser under the workpiece. The closer to the bottom of the carriage you can get makes it easier to cut without over extending the bit.
I like the 80/20 linear bearings for the slides, but they are pricey and you'd need eight, four for the router carriage and four for the cross beam carriage.
Ron