ᐅ Installing a loft door after creating the opening

Hello everyone,

I am planning to install the sliding door shown in the pictures in my new build project.
I would like to create the opening between the master bedroom and child’s bedroom 1 (see construction plan).
Does anyone have experience with the ideal width of such an opening? I was thinking about 2 meters (6.6 feet). The wall is 3.70 meters (12.1 feet) wide.
Any advice is much appreciated.

How much does something like this usually cost?
Does anyone recommend a company or brand for the track and door?
How wide should the passage be?
Any other tips are also welcome.

Pictures are attached.

Well, should the door be able to close the opening completely? Then, if the opening is about 200 cm (79 inches) wide, the door would have to be around 205 cm (81 inches) wide. That leaves you with 165 cm (65 inches) to slide the door either to the right or left, since the wall is only 370 cm (146 inches) wide. The door would then overlap the opening by about 40 cm (16 inches) when it is basically open.

Also, the opening would have to be either at the far right or far left. Alternatively, the door could be double-leaf.