There are many great solid state preamps. Nothing wrong, at all, with using one. I still prefer high end tubed preamps. When I have compared similar prices ss and tubed preamps I have preferred the tubed… they have a more natural and musical presentation. There are probably exceptions.
Controlling amps directly from DACs is not a thing yet. Many people have tried it and most have abandoned it. You end up with great details and a sterile sound. I suspect over the next twenty years this will slowly change as digital dominates the market and analog becomes less main stream.
But for now, unless you want to put out a lot of money, a lot of research time and probably buy you DAC (non-tube) and amp from the same manufacturer, it is better to assume you need a high quality DAC and Preamp.