On stock 14's, I'd probably run 195/50's.
The first number=width in mm
Second number=percent of the width that the sidewall represents
thirds number=wheel size
letters=speed rating

I know with my 15's, I run 205/50's. The tires are still well protected against pot holes, crackes, etc.
The bad thing with the 205's is that I had some rubbing issues, and ended up cutting the lip out of one wheel well. (my car has been through 2 accidents that I didn't know about when I bought it... But that explains MY rubbing issues)
That aside, 205's shouldn't rub, but depending one what tires you get, they may be harder to mount on the rims.