Go figure.
The only nominally republican I know of billionaire is Thiel, who committed the unpardonable sin of supporting Trump. And Trump isn't a doctronairre conservative by any means.
He's pro-gay marriage, but at least he is pro-life in his actions.
Even the "evil" Koch brothers are libertarians.
They are pro liberal causes, but their "sin" is that they support free markets.
I cannot think of another multi-billionaire who is any way "conservative".
The Koch’s are not really libertarian. They are “court libertarians”, meaning they support libertarianism in some superficial ways (legalizing pot and porno). They are not in favor of getting rid of the Fed, or applying the NAP to foreign policy. There is no way they would openly support Trump.
Billionaires do not want to change the system that made them so wealthy.