Brakes are the most powerful force on a motorcycle, attenuating speed in a fraction of the distance it takes to generate it. In order for the rider to scrub the most speed from their motorcycle, the rider needs maximum feel and a firm lever. Although the additional plumbing of ABS brakes has increased the complexity of this modification, braided stainless steel brake lines are the best way to get that directly-connected-to-the-calipers feeling. Many aftermarket companies sell kits with the lines appropriately sized for individual motorcycle models. You can also buy them in cool colors as shown by these Galfer lines.