I’m planning to fit 3 sliding-folding doors to break up a through room. Full height internal wooden doors up to 40mm thickness with glass panels, can you recomend a door kit or the parts required?

Probably the best solution is the Foldaside 240 system You could use either the hinges or pivoted systems but the hinged system requires the first door (the one attached to the frame) to be 29mm plus half the door thickness shorter than the other doors. If you already have equal width doors you would need to go for the pivoted system.