demitch,
My only recommendation will be to stay with the Pentium III or 4 processor. Most music software needs the pentium chip to work properly. Even though the AMD seems to be more efficient, more drivers and software for music is supported by the pentium chip. You can do word processing and internet stuff just fine with the AMD but I think you are also looking to do music as well.
George Kaye
Kaye's Music Scene
Reseda, California