What does it take to develop a money transfer service?

A friend and I want to establish a money transfer service for a particular country that can be a considered multi-billion dollar niche market. We want to establish something like a "Transferwise" for that particular country, however, the problem is that we neither have the software know how, nor have we found till now a currency cloud partner that offers services for that particular country. Could you please let us know how we could build something like "Transferwise"?