I see basically 4 possibilities:
Michelin XZX 165-15, this is a SR rated tyre, up to 180 km/h. I can't remember if Flavia Sport fitted those initially. Good value for money.
Michelin XAS 165-15, this is a HR tyre, up to 210 km/h. Certainly the best, but also very expensive.
Pirelli Cinturato 165-15, CA67 profile, also HR, and quite expensive.
Vredestein Classic 165-15, this is also a HR tyre, and good value for money.
Check prices on the Longstone website.
Vredestein would be my choice, I have them on another quite fast and sporty car, and am very happy.