Renault scenic 300mm discs with mk1 focus rs brembos. You will need brackets to mount them though.
I think they are the same as pug 406 brembos, if so a company in the netherlands called motex performance do the bracketry needed. Don't hold me to it though as the caliper offset may be different !!
But as above no need to upgrade, i did because how cheap i got the parts otherwise i wouldn't have bothered.