A lot of people really favor the Fast Intentions CBE with the Berk HFC. Which exhaust to purchase is an EXTREMELY personal choice though which makes it very difficult to know what's best for you. You really cannot simply go by what someone else thinks is best. Your best bet is to go to your local car shows/meets and physically hear the setups that other Z owners have. Your next option obviously is to listen to the sticky Exhaust Clip Database:
370Z Exhaust Sound Clip data base