Hi,
Good schools for English medium education were usually located around Colombo and Kandy but there were other good schools even in Galle, and there were also some schools run by the church here and there, also provided English medium education. That was the situation when I was there but take a look at it now   I am getting more and more fond of SL my birth country.
I have been to few counties so far I think SL is one of the countries that you meet people without making any effort at all.
Concerning your business plan, If I were you I would have hire a real professional business consultant to get all the government benefit out of it, and a good lawyer to be more safe. All the best!