Ek3 has the same brakes as the ek4 so no need to swap. Since its pre-fl it has drums back, but no worries. Those worth much more in every aspect than 242 discs.
Get a s20 gearbox instead the s40, it will be faster like 1 second up to 100km/h.
I don't think 242 discs would be any benefit. It can cool down but that's all