I have built several DIY (from scratch) pocket doors into my place, fit into metal stud drywall.
I did the wall with two layers: first 22mm OSB onto the studs, then normal drywall sheets for the surface. This gives the wall way more stability (so kids running/kicking against it are no issue), also enables to hang up stuff on it using standard wood screws (just keep documentation where you put cables and pipes in the wall).
For the pockets I pu in a piece of solid wood (to mount the rail for the doors) in the top of the doorway which is then securely fixed with screws through the OSB from the outside. Edges of the pocket walls (at the opening) have been additionally stabilized against flexing by adding 30mm (inner size) steel U profiles (3mm thick) covering both the OSB and the drywall sheet ends.
The door leafs itself are made of a frame of solid wood with a filling of an HPL sheet. In the bottom of the door leaf is a dado for these
, the surroundings of the leaf in the frame are closed with bristle seals.
This together gives a reasonable (for a sliding door) sealing against air movement and noise. Added something similar to this
so the door is flush with the pocket when fully open and springs out at a slight push.
Surely one can buy a complete kit, but they havn't been that hard to DIY. Only thing to remember: to install the rail and test everything (positioning of the leaf open and closed) before actually closing the pocket makes life easier
The Haefle system looks promisiong with the auto-close, will most likely upgrade my rails to it should I ever need to replace the current ones (no indication for this so far, after >5 years of daily use).