More than likely... Racetech
I suspect you will contact Matt Wiley (email@example.com) at Racetech. I do not have personal on road experience with their stuff yet, but am in the midst of installing a gold valve and springs on my R75. I have yet to hear ANYTHING negative about their products or support, except for price, but we are all notoriously cheap. Matt has been super helpful in answering my questions. I will post the build at some point, but it is pretty straightforward so far.
Never underestimate the laxative properties of motorcycling.