Ah! Bet is a new one on me, I'll try and remember that! Sorry for not remembering about your WMS kit, I did remember talking to you but wasn't sure if it went ahead...
You can go pretty silly under 17's, a rough guide to the possible disc sizes is:
14" = 255mm (285mm in some motorsport alloys!)
15" = 280mm (310mm in some motorsport alloys!)
16" = 305mm (335mm in some motorsport alloys!)
17" = 330mm (360mm in some motorsport alloys!)
I would be looking to restock the 280/284mm brackets and next move on to do 298.5/305mm brackets (to cover 298.5mm rotors on bells as well as the 305mm Fiat disc if I can use it on the Punto....depends on the offset).