there was a very informative thread about this recently if youu want to search...but what i learned is cheap rotors off ebay use cheap refurbished metal and when they are crossdrilled and slotted, that makes them even weaker leading to cracking.
ANY Cross DRILLED rotors are inherently weaker. As the gases flow through the rotors where they are drilled it weakens the strength of the rorots. Hence why Roush only has Power Slot rotors Don't get Cross DRILLED, even if they are power slot too. Just get Power Slot. The gases from the brakes escape faster and the rotors are stronger.
www.steeda.com has a whole 13" Cobra Kit. And so does www.mustangtuning.com Both good buisnesses.
Both sites include: Rotors, pads, calipers, and SS brake lines. STEEDA even has a 13 and 14" Brembo set up.
For around town you don't slotted to drilled. You are just going to wear your pads out sooner. The gasses that build act as a form of lubricant (not like oil) but they help prolong padlife. Unfortunaly this is what can cause you to crash at high speed braking. But for around town you don't need them, unless for "bling" factor. I love these little characters, sometimes I write just so I can use them. See