Since you require NO isolation, a resonant buck is an intriguing possibility.
Having said that, the resonant passive components may be quite large, or its values not readily available.
I would do a feasibility study, that in essence means doing some paper-and-pencil calculations, probably some simulations, and then look into your favorite parts distributor to see if those components are available (and at what cost).
You do the same exercise with a full bridge configuration.
I don't think that you can get away without a feasibility study, and the time and effort involved on it. A lot of people here will have lots of opinions. But only cold, hard calculated facts will give you the optimal answer.