As far as sonics are concerned, it depends on what you consider good sound. If you want sonic accuracy, as in low distortion, consider BJT's in the output. 2SA1302, 2SC3281 pairs are powerful with low distortion, and have the lowest beta droop -- which can be a significant source of distortion at low impedances. If choosing MOSFETs, the 2SK1058, 2SJ162 laterals are extremely rugged and low distortion (more than BJTs tho'), and are designed specifically for audio use.
It all depends on what distortion means to you -- some people like more of it, and choose MOSFET designs specifically for that reason. One benefiet of MOSFETs -- they are usually harder to destroy than BJT's =).