Have Hi Spec 280MM solid discs and four pot callipers on the front, and Hi Spec two pot "handbrake" callipers over the vented disc from the Caterham front "big brake" kit on the rears.
Braking is phenomenal, and the larger diameter front discs provide a lot more control over it than smaller discs. Front callipers do not have dust seals and have had no problems with that since fitting them in about 1999.
Pads are Mintex 1144 all around.
I would add that I have had truly excellent service from Hi Spec. over the years. On one occasion they stayed open until 7PM on a Friday night, so that I could collect some new discs.