Ideas for October/November holiday

Hi all, I'm looking for inspiration for our next trip. We could be flexible on dates, but looking for something long haul / tropical with a wow factor, that's also cheap when you get there! !!!128540;

We would need to fly via klm the majority of the route as other half works for them, and we can go via schipol from Norwich.

To give an idea of what we've loved before, our first holiday together, 10 years ago was to Au nang area of Thailand. We lived the people and the place, especially Railey. We love to snorkel on beautiful beaches and white sand, but also like to get out and see things, not just sit on a beach.

My initial idea was Cambodia, a couple of days at Siem Reap to see the temples, then fly to a beautiful beach area. I've looked at Koh Rong Salmon, I read conflicting reports that the beaches are dirty, and the sea full of sewerage, but it does look stunning when I see it.

But where/what would anyone suggest?
The Philippines could be an idea, but I know nothing about where to start.

Places like the Maldives are out of our budget really, and possibly too quiet? We don't need to party, but do like a good evening buzz. We do definitely want longhaul, and both really don't like the likes of Tenerife, been to The Gambia etc.

Places in Europe we've loved has been Parga and the Greek ionian which is just beautiful.

It's such a 1st world problem, but I just need some inspiration! And to make sure we don't hit rainy season!