From “Jiean Robot” in Zhejiang, China. “Zhejiang Sikete Technology co ltd”
Very easy to deal with Chinese company, good customer service, understood my needs, able to customize, and 7 day delivery once TT received. Well priced also, about USD400 each approx .

Photo is before the mounting plates go on to interface the rails and the extrusion.

Well I think I went a bit  too big !   NSS95 for the dual X rails and a smaller NSS75 for the Y gantry. The idea is X gantry has to support (and accelerate )  the Y guide and the gear.
Motion specs for the 75 and 95 are the same, just the loading. In hindsight, NSS75 all round would have been fine.  I went with the ’95 because they were only about 15% more .

75 guide is 7.5 kg, and ’95 is 12.5 kg. Lots of extra Aluminium plate…The 75 guide (Y) is 600 travel. The X is 800 travel,
The guides come with photo-interrupter limit and home switches and cables that can be put on either side of the guide.

There is 780 between the supports so the head on the Y can be quite wide (in Y) and still run full travel.

They are silky smooth… I have run them up with a motor and they scared me….