Everyone knows that now is an international society, more cooperation is not just for their own country. So if you start after the business, you want to make the company more international, you will choose what way? Which market or country is selected?
Short answer: the country / market you actually know. If you go where you don't know the country / market, be prepared to lose the whole initiative and possibly more. This is not to say don't go, but do your research and know not only yourself but also where you want to put your feet. Unless you are the UN, you are required to comply with local authorities wherever you go. In many countries, ignorance is not a protection. What you don't know can hurt you. What you know can be an advantage! Definitely go international!
I would go with the country you know ... where you have the most contacts ... and the best understanding of the market.