Door and drawers are all oak. I've gone with a contrast for the doors, using reclaimed old oak (150 years +) for the door center panels
For the back and side fascia panels I've used a combination of oak and MDF; routed to look like paneling. Now I know I could have used solid wood for the paneling, but pine is going to warp and twist and oak is overkill for something I'm going to paint anyway, so as it is I'm comfortable with using MDF (just this once).
So I've done one row of units, next is more of the same, to do the corner L on the other side of the room.
Hey we even have a modern fridge now, wonders will never cease!