"He wants to [get hitched]," she told PEOPLE Thursday night at London's Nobu, where she showed up for a late-night snack with Madden and her parents. "We talk about it."
In fact, she's already pondering her gown: "I'd wear a beautiful white dress," she said dreamily, "probably Dolce & Gabbana."
The heiress, who is in town promoting her new fragrance, Can Can, couldn't stop gushing about her new beau.
"We are the perfect match," said the 27-year-old (who begins filming her MTV reality show, I Wanna Be Paris's New Best Friend! on Monday). "We don't like being apart, we like to stay with each other as much as we can."
No stranger to marriage proposals, Hilton said that Madden, 29, was different from her previous boyfriends, including ex-fiancés Jason Shaw and Paris Latsis.
"[Benji] is very down to earth," she said. "He's worked very hard on his own. He really has a heart of gold. He'd never do anything to hurt me. He loves and supports me no matter what. He's a really great person."