Uhm. Wire? That's a motherfucker to do but I love Van and he's my husbando so I hope someone else can help.

Milliner's buckram would wrk very well for the brim, you just have to mould it carefully with hot steam (I tend to use the kettle as then I can have a cup of tea). You can get buckram in most fabric stores, or in the furnishing department of department stores.
Tutorials exist but I have none sorry!