Back to the OP's main question ...
On two restorations I've done ('39 1/2-ton and a '49 1.5-ton), I did all my own brake lines. The '39 because I *had* to -- nobody had brake line kits back then for that era. The '49 because I wanted to. I really enjoyed the process on the '49. Granted, it was a frame off and I was just working on a bare, freshly painted chassis. A couple of thoughts about DIY:
1. Get a really good flaring kit. Eastwood has one and some of the other high end tool vendors offer the same thing. The experts can point you to them. Yes, they are expensive. But you make perfect flares every time.
2. There is a learning curve. Enjoy the process and don't get frustrated by a few unusable pieces.
3. Very helpful if you have a little artist in you. Helps with visualizing, and then accurately rendering, compound curves.
4. Approach it as a fun exercise with no end time constraints. I went into the shop those evenings with the thought that I was going to spend the next couple of hours enjoying myself. I did. If I had approached as "I have to get this done by the end of the week" It would not have gone well. When I bent the last line and had a completed system that worked with no leaks, I was super satisfied. I was also a little let down because it was over (too soon, it seemed ...). Everything seemed to get harder and less enjoyable after that ....
FWIW ...
John
