When using the Desert Karts Master Cylinders you will need to find the right fitting for your application. It's very easy to do if your complete brake system is going to be comprised of VW parts. The buggy industry has been driven by the conversion of VW's Bugs into buggies so the fittings are European metric.
If you are going to combine Buggy master cylinders with quad calipers you will need to adapt the lines and fittings.
There are at least four kinds of Brake lines stocked at most automotive parts stores. I don't stock them because shipping can be very expensive due to their size. The stock brake lines come with fittings can be purchased in your neighborhood auto parts store.
The brake lines for specific use have color coded fittings. They are coeded in the following manor:
European Metric are Pink.
Japanese Metric are Blue.
US 3/16" and larger are gold.
The best idea is to use AN fittings. These lines are used in the performance car industry and in aviation. The best part about this type of brake line is you can adapt from the many metric fittings that are available. A good example is:
Converting from our master cylinders (European Metric) to Banshee calipers (Japanese Metric)