I just read this post, so hopefully I'm not too late.
Sound file conversions are easier than ever nowadays. Windows media player can burn a CD from either a WAV, WMA, or MP3 file. All you have to do is to create a "burn list".
The nice thing about the TASCAM GT-R1 is that you can record to either WAV or MP3. However, overdubbing can only be done in WAV file mode.