Batch convert *TO* wav?

Hi - would love it if someone could help...

Just got my first Mac(Book Pro) and really interested in the Automated Folder feature...

I work with a lot of audio, and so was interested to see if there's any way of being able to dump files into a folder and have them converted into 16bit mono wav files?

They start off as MP3s, stereo WAVs, AIFFs and AAC/MP4/M4A files, and occasionally WMAs (but these are not so important). Also of interest would be the ability to drop in video files, and have the soundtrack stripped to a mono WAV, but again, this is not so important.

I've seen the Switch software from NCH and Sample Manager by Audiofile, but neither are quite what I'm after. I'd really like to be able to drop stuff in a folder rather than fire up some software and create a list of files to convert (which is Switch), and Sample Manager doesn't convert *into* WAV.

So is there anything that would be able to handle what I'm after? Any pointers welcome - I've searched through 2 years worth of messages here and haven't come across any recommendations!

thanks (hopefuily) in advance...