Sl R107 engine choice ??

Hello, I’m thinking about buying a nice R107 because I’m already dreaming of it my childhood. Now I have no idea about the engines at all. He should not be a everyday car but honor what to be for weeks and the beautiful days of the year. Which engines are really recommendable? I think the 280er would be enough because racing can’t be done with brakes and suspension from 30 years ago anyway. But is the 280er also empfelenswert ? or rather a 350er ? i de nke the 450 does not have to be, but I just want to know which engine is really to be recommended or whether it is only a matter of taste ….? and what should I pay attention to ? so general weakness etc … thank you in advance ….