Still looking for a designer.
I have been working on the dungeon a lot myself. The plan right now is to have the designer work on either Hyrule Castle, Hyrule Town or the landscape. Whatever meets their fancy. I do have specific plans for the castle (room layout and purpose, just not the content). The overworld positioning is vaguely predetermined (Hyrule in the center, plains below, mountain above. Stuff like that). The town only has a couple of definitive factors (specific house in the upper right corner, inclusion of some houses with specific purposes etc).