The 20-year-old also said she has been inundated with offers from other designers and is finding it difficult to choose, reported People magazine.
"Marchesa make the most amazing dresses, they are definitely one of our options. But so many people want to be involved, I'll probably have 30 dresses at my wedding," she said.
While Cyrus is struggling to choose the right dress, the 20-year-old added she and her fiance aren't getting stressed about the wedding planning, reported People magazine.
"I'm not worried about it, we haven't talked about anything specific. Liam is pretty laid back about everything, it's the best thing ever."
"When the wedding does happen, it's going to be a small, intimate one.