I found the company on internet and contacted them. The answer time was really short. Milo told me everything I had to know about the doors, installation and so on. He also sent me some pics and videos. As I was on the raw phase of construction, it was important to understand the process. So he helped me to consider the dimensions and gaps. I‘ve ordered 8 customized doors, and they are very high quality.
The installation itself as easy as nothing. I‘ve installed by myself w/o any help and difficulties. The frames are pre-mounted, so you just have to install it in the wall opening.
The painting of doors is also easy done. So 5 points for communication, ordering, quality and support. I highly recommend this manufacturer!