I’m after some door runners for a custom made door. The runners will need to be 2 metres wide. The weight of the door will be roughly 40kg. It is not a pocket door, just sliding across the wall. Is there also a way for the door to stop it slamming against the walls?

We do the economical Rollan 40.24 which is suitable for doors up to 40kg.  If you want to go for something which closes the door softly at each end (and your door is at least 840mm wide), we recommend the Perlan SoftStop double draw-in, 2050mm track.  Tracks can be cut down to length.  Links to both those items are highlighted within the text.  You can look at the video of the SoftStop here which shows it in action.