The stock brakes are just ok. You can probably make them work. But everything you do to make your car faster will make life even harder on the brakes.
So there are several things you can do to help the stock brakes out.
In a nutshell: Brake Ducts, Duct Plates, Shims, Fluid
Brake ducts!! I have a set of RooDucts awaiting install. Its a bit of a PITA on the 06/07 due to the windshield washer reservoir. I'm not sure about GR+ install. Then you can get a hub-mounted plate like the Quantum setup to really get the cool air towards the center of the rotor. In addition, you can get titanium shims (Zeckhausen) that, theoretically, help keep the heat from the pads from transferring to the pistons and calipers. Of course you'll want a fancy brake fluid as well.
I dont know if there are fancier rotors that fit the OEM brembos, but a two-piece with nifty internal fins may also help cooling.
But you might be surprised at the math behind a BBK. I wish I still had all the numbers in front of me, but to revitalize my OEM setup I was looking at 1) new seals/boots 2) new race pads 3) new rotors, 4) new brake lines, and probably some other odds and ends I'm forgetting. I think that added up to the better part of a grand!
But you can probably sell your OEM brembos for $400, give or take some. And a new BBK is MSRP of something like $2k, and can probably be had cheaper from a vendor (I know I got a smokin deal). And, IIRC, the long-term ownership costs come down for replacement pads/rotors/etc... since its somewhat "generic" for the BBK and not just your car. And they should last longer. I could be fuzzy on the math.
Anyways, when I did it all out, the BBK was only a few hundred more then the Brembos and was a) better b) cooler (pun intended).
I went with the ST-40 Trophy (totally unnecessary upgrade over the ST-40, but see "b" above). I did a LOT of research on BBKs, and the ST-40 is really the sweet spot, for me, for price and performance. I would've loved to go AP Racing, Alcon, etc... but I couldnt justify that price.
