I've used Amalia's songs from She Loves Me for auditions. I know "Vanilla Ice Cream" is overdone, but it's fun and shows off the soprano range well. "Will He Like Me" isn't quite as uptempo, but it's still a very nice song.
"And This Is My Beloved" from Kismet is gorgeous, and you can take the last "beloved" up an octave, which is always fun.
A lot of Gershwin and Porter songs were originally written in fairly high keys as well. Try "It's De-Lovely."
I don't know how high or how coloratura your range is, but if you really want to knock them dead, try "Italian Street Song" from Naughty Marietta.
"Wilkins, after all these years, are you trying to be funny?"