Great! Implementing an imagery provider is a relatively simple matter of implementing the ImageryProvider interface:
A good example to start with is the TileMapServiceImageryProvider:
I think Google Earth may use a similar tile layout to this one, in which case it will be very easy. If not, we can talk about the next steps.
By the way, you should check out the Contributor’s Guide if you haven’t already:
If you get this working, we’d love to incorporate it into Cesium, but we’ll need you to sign the Contributor’s License Agreement. There’s one for individuals and one for corporations:
It essentially just says that you own your contributions and that we’re allowed to use them. If you’re doing this on company time, it may be worth getting started on the process now because it may take a little while for your legal folks to sign off on it.