To answer a few more questions : My Supra is the 6 speed manual and has about 80,000 miles on the clock. It is mostly 'stock' but with some basic upgrades. It is running about 400bhp+ on the stock factory turbos and I have a Blitz SBC i-colour Boost controller to keep boost levels 'safe'.
The full spec of my car is on this link : http://www.mkivsupra.net/vbb/vbpicgallery.php?do=view&g=51
One of the first things I changed when I got my Supra was the brakes. The original factory ones didn't have a nice feel to them, although they did perform well enough. I uprated the brake pads, brake discs, and brake fluid. And the difference was very noticable. I took this setup to the N'ring for the first time and the brakes performed really good.
I find that there was no reason to put any bigger brakes on the car after that.
I never found any brake fade with the stock set up, it was just that the 'feel' of them was not good. when you press the brake pedal there was no first 'bite'. But I also had to press the brake pedal hard to get a hard stop. With the brake set up I have now I get a good first 'bite' on the brakes and I don't need to push as hard to get the car to stop.
Tyres also make a very big difference of course. If you have very grippy tyres then you need good brakes to go with them.
There are not very many UK-spec supras left these days so I am not wanting to change it too much or do anything to it which can not be un-done easily enough.