You do realize that without Western support current Saudi government will fall victim to internal opposition, which is much more fundamentalist and is not significantly different from ISIS, right?
I'd say that'd remain to be seen. ISIS essentially is a doomsday cult. A fundamentalist state like that isn't sustainable in the long run.
Make no mistake though, the Western world doesn't prop up the Saudi government out of moral reasons. They do this because of Saudi-Arabia's significance to the oil economy. The House of Saud in exchange complies with the economic - and to some extent - political demands of the Western world.
