Having done many miles on a Golden Flash combo I can say the tyres work hard. You need a stiff tyre that holds its shape cornering as there's a lot of side force. You also want a flatter profile, there no leaning so you want tread on the road. The front spends a lot of its time going slightly sideways. We would use Avon SM mk2 on all the wheels as they are stiff and square-ish profile, but they were cheap, now I see they have jacked the prices up a lot.