I'm running the Brembo brakes for my grand touring 2006 350z on all 4 wheels. The brake pad is starting to go bad. My macanic say I have to replace all 4 wheels brake pads and rotors. Was wondering if I should replace all 4 or just do the front?And were would be the best site to buy them for a reasonable price?Also what should I get brembo brake pads or Hawk or Stop Tech? And what material composite or other material?