Hi there, congratulations on a lovely looking saloon and for taking it out on the track already
Brakes - There are 3 basic options -
- None OEM 390mm Steel Disc Upgrade
- Bigger than OEM Steel Disc Upgrade
- OEM/Aftermarket Ceramic Disc Upgrade
None OEM 390 Steel Disc
My preference for fast road/track is the following - AP Racing 390mm 2 piece Discs, Ferodo DS2500 Pads (or Pagid RS29), better Brake Fluid (ATE Type 200, Castrol SRF, Motul 600, AP Racing etc), HEL Brake Lines & VW Phaeton Cooling Ducts with Backing Plate.
There are other discs/pads etc but I found that the above gave me the best mix of road and track ability. The cost of the above is £800 discs, £250 pads, £30 fluid, £80 lines and £100 ducts IIRC.
Bigger than OEM Steel Disc Upgrade
I went with the following after my 900+ conversion - AP Racing 410mm 2 piece Disc, AP Racing DS25 pads, Castrol SRF, custom HEL Brake Lines and no backing plates on the brake discs for maximum cooling.
Again there are other options as the OEM calipers will take a 405mm disc so Brembo GT etc will fit. The cost for mine was around £2600 inc the custom lines.
OEM/Aftermarket Ceramic Disc Upgrade
The OEM ceramics are expensive (£4000-6000 2nd hand set or £14000 new) but track based ceramics by someone like Movit etc are even more expensive. Again, better fluid is a must but there isn't much pad choice avaialble and I think (not 100% sure) brake lines would have to be custom made.
The Ceramic vs Steel disc discussion for "on the Track use" can get a little heated in here so I'd suggest you use the search function where you'll find there's already quite a few threads about track-based brakes with lots of information in them.
Hope that helps.