I used a K8 master cylinder on my K6 to eliminate the pressure switch. There is a mechanical switch on the K8 MC that can be used for your brake light. When you do that, you can run a brake line from the master cylinder down to the hard line (no longer needing the stopover for the pressure switch block). Buying one brake line from top to bottom is about half as much as buying the two part setup with the pressure switch. I guess the ends and their attachment are the expensive part.
I went stainless with a black coating. My brake line now looks "thinner" than factory but unless you were looking for it, you wouldn't see it.
The one downside to consider if you want to use a K8 master cylinder is that the brake lever is a little different and probably kind of rare because it has a shape that accommodates the mechanical switch. (if you need pics, I can post them)
The folks I used for a brake line are listed below. It cost me 60-ish (if I recall correctly - 120-ish for 2 lines) shipped. Very nice people to deal with. If you need to measure your length (they'll want to know), use a piece of rubber hose (fuel hose will do). They'll know what ends you need.
http://www.spieglerusa.com/cfm/brakelines.cfm
