Hi Nikos, If you want improved braking, then you need to be looking at big brake kits. FD do them, as do others, but stitch up your back pocket, 'cos you won't be putting your wallet in it for some time. If you want to just renew your brakes, then go for the Brembo 550 disks and and pads of your choosing. The coding won't be the same as the OEM 4200, but I run them on my '04 4200 (as do others) and they're just fine. Like Parisien, I run them with green gripper pads. If renewal is all you need, then why shell out many hundreds of your hard earned when perfectly fine disks can be had at a fraction of the price. A disk is a robust, but simple piece of engineering and if these can stop a 5.5 litre V12 with nearly 500 horses, then they can stop a 4200.
A relatively inexpensive braking improvement would be to replace the brake hoses with solid / braided pipes. Not a massive difference, but a bit surer.