what tool do you use for MIDI to wavemp3

Hello Everyone,

I have successfully loaded my Steinway piano soundfonts into my SoundBlaster card and my midi piano files sound great. However, when I convert them to mp3 using iTunes, they lose their Steinway font sound and revert back to that synthetic midi piano sound. When I burn the converted mp3 files to CD, they'll play in my CD player, but not with the concert hall piano sound I had hoped for. Does anyone know of a way to convert midi to mp3 while retaining the soundfont information? Or is it just not possible?
Thanks in advance,

Dale