Thanks all. EuroCarParts has additional fitment details which say...
288mm front disks = 160mm pads
253mm rear disks = 87mm pads.
Occurred to me afterwards that I only had two tyres off so probably missed the wear sensor.
Any idea when then wear sensor triggers? Mechanic estimated 5k left in the brakes. Car is on 51k so would be about right.
You can get Pagid/Brembo off eurocarparts or carparts4less.
Put your reg and and it will show the right parts, Cupra usually shows a few because of the upgraded brakes.