Advice on Schools please! (Colombo)

We are moving from London to Sri Lanka at the end of December, ideally near Mirissa or Galle. Can anyone recommend schools there that might be suitable for our children; 8 year old girl and 5 year old boy?
We had heard mixed reports about the quality of international schools with some people suggesting that the state schools are better quality - does anyone have any experience of this? Is there anyone who has checked out both options?

Thank you in advance for any help, Frances