Cache, I did the undertail myself. I ordered it from Mototech and within a few days I had it.
Installation required cutting the stock fender a lot. I kept that part so I can make photos of it as a guide for other installations. The fender cuts easily, but there are tight spots, so patience is key.
In my opinion, the Mototech undertail with extra turn signals fits the Busa well. I did not have to cut it at all. The tabs lined up with the stock fender holes -- you still have to drill each hole in the undertail.
The hardest part of the whole installation was removing the plastics from the tail of the bike so I could get started. Everything else went smoothly.
If anyone wants some more detail on the undertail or installation, let me know.
Oh, and on the turn signals up front. They really are clear, like glass. I hadn't expected it, but in the end I like them that way. With the 'titanium' bulbs, they have a nice chrome look and look similar to the headlights.