You could use ledged and braced doors. This type is still mostly used on sheds, but for a house will be better made and stronger.
Or ledged, braced and framed, which is better.
Or a boarded style, sometimes called Tudor or Elizabethan, which is flat on the outward face, but not on the room face.
If you want the doors to block sound well, get a 44mm door, which will be more solid and heavy, and give an impression of quality when you handle it. Light insubstantial doors feel very flimsy.
You could get a variety of second-hand doors, especially if you buy ones that were external doors (they are more substantial) or from old houses that were large and expensive when they were built. You can cut down a door if it is a bit too big.
Panelled doors are better but I don't know when they became common. They are made by joiners, not carpenters.
Any carpenter can make a door frame, it it just a piece of wood cut into three pieces and simply jointed, screwed to the wall. Actual oak will not be authentic indoors. Because of the way they are wedged and fitted, they will accomodate wall openings that are irregular or out of square.