Its a tricky one this...
The fat arches of the 16v make fitting 17s or 18s a cinch, but they handle way better on 15s.
I had some 16s with 205/45 profile tyres, but chopped them in for some refurbished original Phase2s with 195/50 tyres. The "handling" is way better on the limit now, although the grip is a tiny bit less - but I pefer it that way as I can control it on the limit a bit easier.
Its only my opinion, but I also reckon that original 16v wheels look very good anyway. Aftermarket wheels date; original wheels "mature" with the car.
My flatmate has a 16v on 17s and it is not lowered - I reckon it looks a bit cack!