Originally Posted by OptionZero

First, a correction:
The Akebono calipers come stock on sport and nismo models - the term "BBK" is used on kits that go ABOVE stock stuff

Second, a point to clarify:
You have the calipers; you do not have the rotors?

If so, then YES YOU NEED THE ROTORS THAT MATCH THE CALIPERS. You can get blanks from your local autoparts store for pretty cheap (o'reillys, kragen, autozone), these will be fine for everything up to light track duty

If you want to look cool at your local meet, you can find cross drilled, slotted, or combo rotors that are sized for the akebono calipers

if you need additional brake cooling, you can get 2-piece rotors from Z1, DBA, or Racing brake that have various options and also will be much lighter (but more expensive)

If you need additional braking power, you should upgrading pads/tires

If you are pushing 500hp on the race track, you should be shopping at Endless, Brembo, AP Racing, etc for a complete caliper/rotor upgrade (or "big brake kit")