To summarise the current state of this discussion as I understand it,
the hooks we are currently thinking of defining are:

def get_build_wheel_requires(config_settings)
def prepare_wheel_metadata(metadata_directory, config_settings)
def build_wheel(wheel_directory, config_settings, build_directory=None,
metadata_directory=None)

def get_build_sdist_requires(config_settings)
def build_sdist(sdist_directory, config_settings[,
build_directory=None])  # Last param under discussion

I know we were also discussing a different naming scheme, but I've
forgotten what names were proposed, and don't have time to find the
relevant email again. Could someone produce a copy of the list above
with the proposed names substituted?