Korg MA30
I'm using this, has output for earphones.
Korg MM2
I used this before, and I dont recommend it because it's rather fragile. If you like micro devices and handle stuff well, you can get this.
Citymusic + Luthermusic stock Korg metronomes. You can also look elsewhere. There's just too many available. Go down Penisula Plaza and keep a lookout for them.