Darrell McDaniel not sure if you have had a response from Servicemax in regards to GPS tracking. We had a meeting today with one of Servicemax partners called MapAnything the offer a fully integrated solution with the Salesforce platform for live vehicle tracking. I have provided a link to their website below and will provide an update once a solution is rolled out across our vehicle fleet.
Most GPS solutions offer API's that either let you push or fetch data. We are currently exploring the same.
We already have a solution for the GPS monitoring. A web-service will likely handle the rest.
For what its worth geotab is the gps solutions provider. Its pretty comprehensive.