What size of alloys can fit on a Peugeot 206 1.1 zest?

I put 17's on mine and the wheel kept hitting the top of the wheel arch when going over speedbumps and holes in the road and when there was weight in the back it would grind against the top of the arch, so they had to come off as i didnt want to change the suspension, I now have 15's on and it works well with the origonal suspension so i would go for them if you dont want to change the suspension, the 17's looked better but arnt worth it when you have to change suspension