I am also living through something quite similar. Last year I lived in a residence around my university campus, and that living arrangement allowed me to meet all sorts of people coming from around the world. Slowly I became friends with this Japanese girl, who had (and still has) a quite unique personality lol. We talked and chilled alot together, but things never got serious. So at the end of that year she had to go back to Japan, we both found it quite difficult, but throughout the summer up to this day we have been talking via facebook on a daily basis on skyping on a weekly basis.
I was never entirely sure how I stood on a emotional level towards her, until recently where (through various events) I discovered how deep my feelings for her were. Anyhow, I told her how I felt and she responded fairly positively, put she is living through difficult emotional times (she is trying to cope with an eating problem, ala anorexia, and possible Bipolarity)
So for a while now I have been considering if a long-term relationship is viable, and I was wondering the same thing as you are!
Recently I decided to change my major and I am now eligible for an exchange to Japan next year in the same city where she is from... So that is fantastic lol.
(I hope I am not stealing your thread or anything like that, just thinking this might help you someway)
In the end, I think you should go ahead with your plans man! These long-term relationships are based heavily on mutual trust. Live in the right now, and go with your feelings