Need Reccomendations For External Flash Options - Samsung NX1000

The small flash which was bundled with the NX1000 (SEF-8A) is not very consistent, some shots are underexposed, some are over exposed and the flash can't be used in M mode.

I was looking at the other Samsung external flashes but I really don't know much about them. My 3rd option was to use a Nikon SB-400, tape off all the contacts except the center and use it in M mode exclusively.

I would appreciate comments from Samsung users who have experienced with Samsung flashes, 3rd party flashes etc. to see what is the best option to replace the tiny kit flash that came wioth the NX1000