I don't know if it's a recent design change or not but changing the pads on my endless kit is the same as the stock brembos (very easy). You don't have to take the caliper off.

To the original poster: in terms of the rear brakes, Brembo doesn't make aftermarket BBK for the rear of the Z so if you want a matching set, 'No Brembos For You!"

The Endless front and rear kit will run you over $7000.

For your purposes, I would go with the Stoptech 14" in the front and the 13" rear kit. They make a 14" rear kit but it's not necessary for such a big rotor back there even if you track the car. You're also going to take a hit on performance due to the increased rotational weight of the bigger rotor and the larger caliper. Get the 13" unless you want the additional bling of the 14"s.