It's a good idea to make sure your braking system is in good working order, but you do not necessarily need to upgrade your brakes.
The two big variables that put heat into your brakes are the mass of your car and how severely you are trying to decellearte. With the SC kit, you really haven't significantly changed either of those. The SC kit will change how quickly you can accelerate, but when it comes time to brake it only matters how fast you are going, not how you got there.
Insofar as brake fade goes, the issue there is how quick you are cycling between braking periods. If that time is too short, the brake system doesn't have time to shed all the heat you put in to it from one braking period before you start putting heat into again at the next braking period. That's the issue faced by cars on curvy tracks and why they use bigger brakes to increase the ability of the system to absorb and shed heat. Off the track though, while bigger brakes offer the same benefit, you don't necessarily need them because you also have the option of slowing the h3ll down and not driving like a jack@ss. (not that I'm accusing of that, just making a general point).
The important thing to keep in mind is that while bigger brakes do have benefits, but they also have penalties, namely increased costs and increased unsprung weight (although by spending enough money you can avoid the wieght issue). The bottom line advice is to try and seperate out how much you want bigger brakes from how much you need bigger brakes. If you haven't had fade problems before the SC kit, you shouldn't have them after it assuming your driving habits don't get too nutty. If you want for larger brakes is the dominant issue, then by all means get them. Otherwise, I'd focus on optimizing the brakes you've got with fluid, pad, and rotor choices.