tried to use search button, but it tells me it is not able to find monza 160 engine oil here

I would like to ask you; do you have any recommendation for engine oil?
In manual for Monza 160 is written Agip F.1 racing or multigrade SAE 40.
But what to choose these days?
I have found some Ravenol brand for historic vehicles, but..
Mineral, synth, semi-synth. I dont know nothing about engine oil.
Thank you