Could you clarify what you’re looking for, exactly? You say you’re in need of a GM but seem to already have the foundation of a setting and narrative premise laid out. Traditionally, that’d make you the GM - are you looking for a co-GM to share the workload?

One thing to keep in mind is not to get stuck in the ‘worldbuiling phase.’ RPs die before they start because people stress minutiae and background details and keep adding more and more superficial elements without actually getting the RP started. 

The most important thing in a RP should be the characters, as it is in traditional novels and literature. And players are responsible for those characters.