Suggest me a route

Hey Guys.
In preperation for our long ride down to le Mans for MotoGP my bro in law and I are wanting to do a couple of 300-400 mile "Test Runs" to check our luggage settings etc. We're hopefully doing one early this Sunday starting out from West Molesey area and then heading down to Box Hill. Planned start is at 6 AM. (Sorry neighbours!! )
After box hill I'm a little lost as to a decent route. Any suggestions?

Thanks