Well... as above. 195/60x14 will fit. It's 2% bigger in circumference than a 185/60x14 so your speedo' will read 2% lower than it does at the moment (though your 3% speedo error is pretty good.. mine is more like 6% compared to GPS).
I think 185/60x14 was the same size tyre that was fitted to the last Alfa 33's so it's a small size by modern standards. I think all the later 145/6 had 15" .. in the UK at least. If you find a set of 205/40x17 wheels and tyres in your garage... then they fit too..
I never proved that I fixed why my headlamp bulbs were blowing.. I cleaned up the Earth connections on each side of the engine bay and that helped. But before the new bulbs blew or didn't blow, I fitted an HID kit.. 55W-5000k
The ballasts are AC.. so they act as a transformer.
If the car is still sending too many volts then the ballasts are better able to absorb it. I haven't had any bulb or ballast problems since I fitted them on 9th December... so nearly 4 months. The bulbs would last just 4 or 6 weeks before..
I *think* the problem was vibration or resonance... since the bulbs only blew after I fitted a "slightly cheeky" exhaust..
And the other bulbs in the car were all fine. I've only needed a couple of number plate bulbs in 4 years..
The HID bulbs have no filament so they're obviously not affected by vibrations. It's worth putting some in there..