Eric,
Regardless of whether the "application" is designed and developed in Boston/US/India or wherever, you will need a statement of requirements. And from experience, the more effort you put into ensuring the clarity and thoroughness of the requirements, the better. In addition, supplying test data and acceptance criteria will help you get a product more focused on your needs.
The analogy here is building a house. You don't tell the developer/builder ---build me a house. Better to start with some details, rooms, floors.... Even better is a blueprint.
Good luck with your project. I would like to hear back on the results.