I don't use iTunes but what I read is that the MP3 encoder is not any good. The blogs say the reason is that Apple wants you to use (for obvious reasons) their AAC format and not MP3. My opinion is that the best MP3 encoder out there is the LAME. It's free, open-source, and is available at

http://www.hydrogenaudio.org/forums/index.php?showforum=55

Best thing is to make your WAV file in BIAB and leave it as such. If space is a limitation, investigate lossless formats such as FLAC, WMA lossless, etc. which will compress the WAV by roughly half keeping all of the audio fidelity. Nothing is lost. You will have the best possible sound given that your original RT was WMA 160. If you must convert, there are plenty of conversion front-end GUIs are out there. Avoid using the BIAB built-in MP3 conversion as you are restricted to what codecs you have installed in Windows.

As I mentioned in my earlier post, you won't get any better quality than the original 160 WMA files no matter what you convert them to. You should try to minimize your conversions to avoid the transcoding issues.

Rachael