The tyre/wheel is what I've had on ever since acquiring the car 8/9 years ago.Out of interest what wheels do you currently have on your car as the tyre sizes you have fitted are non-standard size for the A2, a photo would be good if you could add one?
Regarding more comfort, as others have said if your suspension is all good then a deeper section sidewall (which any smaller 15" set of wheels will allow) will be an improvement, coupled with the correct tyre pressures on good quality tyres, well balanced to the wheels