Have bought SONY's audio Noise Reduction plug in - it works very, very well - my only problem is that I can only see it /use it under Vegas 9.0e 32 bit - not in the 64 bit version.
I use it in 32 bit Vegas or in 32 bit Sound Forge. I know that is a pain, but since it is a non-real-time FX, I just right click and open it in Sound Forge where I do the processing.