Being a girl I don't really can't say what to do. However I've read posts on other forums that suggest using Harold Hill's (Music Man) songs, for example "The Sadder, but Wiser Girl." Or "What do I Need with Love?" from Thoroughly Modern Millie. While Sky and Jimmy don't have much in commen per se, the song matches what Sky goes through when trying to deny he's fallen for Sarah.
All I can think of when I hear Guys & Dolls is "Luck Be A Lady" running through my head, which makes me think Sinatra. Perhaps if you too are a crooner you could get away with doing one of his songs...
Break a leg at your audition!
Currently~ Miss Myrna Thorn in Ruthless! the Musical
Recently~ Emma Carew (Jekyll & Hyde), Sister Mary Leo (Nunsense), Demeter (Cats), Tzeitel (Fiddler on the Roof)