Michelin (any) 205-55-16 V. They know a thing or two about safe tyres and handling.
Continental or Pirelli as second or third choice.
There was a reason why Alfa decided on that size, width and profile... It works when kept in good condition.
Any tyre that is below 4.5mm of tread wear looses 50% of it's original grip and handling characteristics. Lets not forget, 1.6mm is the bare legal minimum, not a guideline to when a tyre looses it's efficiency!
Don't ever skimp on tyres....
It's the only thing that is in contact with the road surface, bigger brakes, pretty alloys and trick suspension make no difference when you are upside down in a hedge row wishing you spent the extra on the tyre's...
Trust me, It's my job to find out why a car has decided to deviate from its normal direction and 90% of these "accident's" can be directly contributed to poor tyre choice/ upkeep and lack of maintenance foremost!
An example of the worst and easiest investigation I attended was an 02 Ford Focus with 4 part worn tyres with a maximum of 2.5mm an all treads and 4 different brands and pattern fitted! and he wondered why he ended up in hospital for three month, permanently disabled and a car that was a complete write off... That was a 45mph collision with a tree on a 20% right hand bend on a country road that was slightly damp!
It's far more cost effective and safer to fit the correct size, quality new tyres than to change the tyre aspect ratio/suspension or brake upgrade... Do this first.... The results are dramatic