DS10 has to dress a Ken doll as Walt so not a big a challenge as you but from the pictures we have seen, we were leaning to a suit and she could have a pointer pointing at EPCOT or a tux and have him hold some Oscars like when he was at the Academy awards. Do you have a black jacket and pant she could wear? Get some gold foil to wrap around somethings to look like an award. Maybe a tux rental place might be able to give you a broken bow tie that you could pin.
Good luck.