I went to 15 inch wheels on my previous Beta Spyder and have Azev A 7x15 waiting to go on my Beta Spyder currently being painted. On the Spyder 195 is as wide as you can go without rolling the rear arch. Many people have fitted Integrale 7x15 or Thema 7.15 wheels. Personally I think the cars look better on them and handling is improved. Be aware if you do not have power steering bigger tyres means stronger arms when parking. With power steering the sometimes too light steering dis appears and you can add 1.5 degrees negative camber at the front for sharper turn in.
Eric
Just curious Eric have you had 205 tyres on a coupé? At some time in the distant future I'll have to make a decision for my VX and 205/50 is a better selection than 195/55 which are I believe the nearest rolling radius