Is there a preferred way to synchronize a remote database to a server version, across a Wide area network?

First, what do you mean by synchronization?

Second, what do you expect or need to happen?

Those two questions will largely determine, both the feasability and complexity of the solution. They will also make it possible to answer your question accurately for your situation.

Third, what is the configuration of your WAN? Speeds, OSs, hardware and software in use, reliability, etc.

This question is of lesser importance to the general concept, but critical to a specific implementation.