There is no doubt that SS Lines and high performance fluid would be better than stock. That is why they make them. The real question is do you need them?
I track my car as often as I can and use Oem rotors, Oem fluid, and Oem lines with a dedicated track pad. I have never had a problem or experienced any brake fade. The weakest link in the system has always been the tires which are Toyo T1R's. The brakes will over power the tires and available traction every time with this set up. I do have to change the fluid after every trackday though.
So with that being said, if you want to get fancy with your brake set up go ahead. It certainly won't hurt anything but the stock set up works well on the track so you will probably be hard pressed to over work it on the street.