I don't know that there's any particular etiquette, but personally, I'd go for the source build over the binary repackaging.
If you were feeling generous, you could make the script respond to a variable such as PACKBIN:
Code:
if [ "$PACKBIN" == "yes" ]; then
# don't compile the source, just extract and repackage the binaries
else
# go through the process of building from source
fi
This way, you get to do both
This might be useful if people don't want to wait for the compile to finish, or if it fails for some magic reason.
edit: Also, are there binaries for all architectures (32 and 64 bit)? If not, then source is probably the most appropriate because then everyone can use it, whether they're on slackware 32 bit, or slackware 64 bit.