So long as you have the OEM brake lines and handlebars on your machine, there's no need to order any other brake components in order to fit the Hot Legs set up. You will, however, have to make a few changes to the OEM brake line set up in order to install the Hog Legs front forks.
The kit comes with additional brake line for joining one brake caliper to the other. That is to say, the stock brake line feeds the brake caliper that sits behind the fork and then, using the included banjo bolt and brake line, that caliper feeds the front brake caliper.