Try Waves IDR, or Cooledit.
I know of many Nuendo pros, who use Cool edit! Don´t get carried away from Steinbergs "UV22" hype. They only added the dither noise whithout the Apogee SR-conversion. So it´s not the same as the original Apogee-UV.....
Cool Edit Pro does a very good job at this.
Put a check in the Pre/Post filter box and move the Low/High quality slider to 400. This will get you very good results.