They just added displacement last year. If the Ducatis prove too powerful as in consecutive races with all Ducs at the front of the field then they'll supposedly be somehow restricted, at least that was the plan for last year.
Seems you want the look and not the hassel. So the aforementioned ducatis, triumph thruxton, moto guzzi v11, for new models. gb500 honda arnt made anymore but fit the bill, I'm sure there are others, but theres a start for you.