The pitch for studs is 98mm you will find the five stud wheels from alfa cars fit , Have some from alfa 147 on mine 205/50/17
have a look on ebay paid £98 for a set Be quick every body will be looking
Now !
I bought a set off a 156 alfa, i had to fit 5mm spacers on the front as they just touched the callipers. The tyres are 225x40x18. They stand exactly the same height as my standard wheels, so the speedo is true & it hasnt altered the gearing. Hope this helps