I think you can buy lenghs of metric and bubble flares at say NAPA but I am not fimilar with your exact application. One of my vehicles I had to put adaptors on the wheel cylinders, cant remember which one. The first full line job was on my Dakota and I did it all with premade lenghts. I must have 5 brass unions on that thing. I didnt like it but they never leaked. I am now doing that same job again, it was 6 years ago.
Inline tube has tools for bubble flare but I saw no metric fittings. http://inlinetube.com/
Do you need metric tube for metric fittings ? It may be possible to reuse fittings if you have axcess to flaring tool, and their not rusted badly, might be vise grip wrench though. I know it sound like cob but really its survival. I had to reuse the fittings at master cylinder but they certainly dont get the corrosion as the down unders do.