Success depends on what you like.
Recommend Lucy Niay if you want the eye-candy: younger, skinnier gals, cute face (lucy), and don't mind getting less pse-type action.
Niay drives.
Recommend Mia Hayun if you want the pse-type action, and don't mind the non-eye candy: hayun: pretty, skinny but older; mia: younger, but not skinny.
Hayun drives.
I do both depending on my mood. Generally prefer the looks, but sometimes really need something stronger to clear the pipes.