I don't mean to be a party pooper, but I usually just...
for f in *.wav ; do sox "$f" -D -r16574 -b8 "$f".svx8 ; done
...when I wanna convert WAV to IFF samples on my Mac. Personally i convert to RAW (replace .svx8 to .raw) and use an ungodly amount of decimals for the sample rate (I want it to hit C-3 equivalent in ProTracker on a PAL Amiga). My samples are usually already in mono but it's just a matter of adding
if you wanna mix down a stereo file to a mono file. Or
for a 4-channel WAV etc.