Mazda's RX7 FD3S once held the record for the best stopping performance production car in the world, and although technology moves on to slightly better things, it's still excepted that unless you are looking at serious track work, your RX7 FD still has some very impressive stopping power. If coupled with up rated disc's and up rated pads this are more than sufficient to keep your RX7 top of its performance.
Remembering that for every 1kg of un-sprung weight you add to the car is like adding 8kg of overall weight to the car, so on a stock or fast street car, adding a big brake kit is equivalent to adding approx 80 to 100 kg of weight. In my opinion pointless unless you have the bhp or track car to match the performance needed.

RotaryArt Mazda RX7 FD3S stock replacment brake pads.

RotaryArt Mazda RX7 FD3S brake discs, plain and grooved.