The yamaha R6's and R1's come factory with a Brembo front brake master cylinder. You can pick 1 up on eBay for less than $100 if your patient. It's a direct swap on a Gen1 busa. I have 1 in mine along with SS brake line. Then you can grab up a set of EBC HH or Xtreme brake pads and that will make a difference but ultimately if you want 1 or 2 finger stop on a dime capability your gonna need to upgrade your calipers as well. I have 65mm Brembo gold line calipers on my busa. Again picked up a nice used set on eBay fairly cheap and a set of conversion brackets