why would you do that......???anyway..q5 is more then enough...
Use ogg at quality 4 instead of mpc for more space savings.
MPC is a little better than Ogg and WMApro,but MPC and Ogg files size is more than WMApro.
Encoding mp3 to mpc is evil, it introduces bad artefacts.The other way around, mpc to mp3, would be acceptable.