Considering it's for 24 hours, any of those girls with martial arts will probably kill you before... attending to calls of nature right next to you... even if you were on your best behaviour. So for a better chance of making it out in one piece go with WYY.

But the above risk aside, I'd go with Guo Xiang, the 20 year old, start-of-HSDS version. She's very friendly, approachable, and interesting to talk with.