The standard brakes were a 256mm disc. Fitting the sport brakes to the Mk1 or Mk2 is a common upgrade, you will need the sport brake lines, callipers and calliper carriers if you want to do the conversion.
Mazda MX5 Mk2 Key Blank OE Mazda years 1999-2003 Part number 905-877
Mazda MX5 mk2 mk2.5 NB NBFL Heater Blower Fan Motor Assembly
Mazda MX5 Mk2 Mk2.5 - Replacement outer sill panels - LH - 1998-2005 , MXV30361
Mazda MX5 mk2 and mk2.5 bilstein shock absorber uprated lower bush set x4 MX-5
HT ignition leads and NGK spark plug set, Mazda MX5 mk2 or mk2.5 1.6 1998-2005
Mazda MX5 - Mk2 (NB) 98-05 - CRANKSHAFT SENSOR - 1.6 and 1.8 - Crank Shaft Mk2.5