1) I would stay away from most Full ATX fanless designs. They still generate heat and if it’s in a cabinet that will need to be dissipated somehow. If it’s a smallish system, you could use a PicoPSU style PSU however. They are so efficient that you don’t need cooling. That said, most 120mm PSU will be quiet enough that it’s not a problem.
2) It depends what you’re looking for. Most of those chassis aren’t going to have the same fit and finish of the all Aluminum Moneual or Wesena cases, but it might not matter either if all you’ll see is the face plate.
One benefit of the Moneual cases is that you can run LCDWriter to handle the internal IR, and use its process specific keymaps to customize what the buttons do per application.