Yes, it can be done. How much money do you have?
Since you're willing to spend money (lead acid won't get you 60 miles at highway speeds) and need higher efficiency (again, given your range goals), I'd say you'd be better off looking for a permanant magnet Etek style motor, like Ben Nelson used in his e-motorbike:
http://ecomodder.com/forum/showthrea...rsion-599.html
....rather than a series DC motor.