Google Maps Integration into Salesforce for Lead / Opportunity Records to Display Distances / Routers

We utilise both the lead and opportunity objects to display an address where the project where will occur (street address in Google), what we need is the visualforce map to display the route to the address from the companies main office which will need to output a distance and a route. The "default from address" will be set and permanent, however the "to address" which pull from fields on the record as per screenshot. Needs to be used on both lead / opportunity and a custom object. Start with leads and cookie cut to other objects.