the only thing I miss is the big preview window in the file manager

I may be misinterpreting you, but I think this is a thing with Dolphin. It has a preview pane, which supports all the file types I commonly interact with (F11), which can be dragged to resize bigger or smaller.

I haven’t used any preview thing on Windows, which is why I think I may be misunderstanding.

Anyways if you haven’t tried Dolphin, maybe it has a solution for you (made by kde project, but I believe it should be installable for any desktop environment)