collective.geo.fastkml does support Polygons and MultiPolygons with holes. Depending how many holes your polygons have it may take longer to generate you KML file with collective.geo.fastkml (as collective.geo.kml ignores the holes). Generally collective.geo.fastkml is slightly faster than collective.geo.kml and produces smaller files.
The style for polygons is created from the linestyle and polygonstyle so polygons can have an outline that is diffrent from the polygon fill style
collective.geo.fastkml does not have an interface of its own, it just overrides the kml-document view of collective.geo.kml.
collective.geo.fastkml to the list of eggs to install, e.g.
[buildout] ... eggs = ... collective.geo.fastkml
Re-run buildout, e.g. with
Restart Plone and activate the product in Plones Add-on configuration section.