Have you thought of South Africa? Your kids are old enough now to enjoy seeing the animals in the Kruger Game Park which is self drive (too young for most of the private game reserves) - and which is ridiculously cheap if you book it direct.
SOoth Africa really is "a world in one country", so you could choose whatever interests you - a beach holiday on the Indian Ocean in Durban or the Wild Coast, seeing the wild animals in the game reserves (there's nothing like seeing elephants, giraffes or hippos in the wild, and if you're lucky you'll see lion or even leopard), the wine trails in the Cape (for you and your partner!), plus stunning scenery in the Cape, the Drakensburg, the escarpment - all over!
It's not a third world country, so the only thing you need to really worry about is malaria in the Kruger - and then only really if you're going in their summer (October through to April). Hepatitis vaccinations and Typhoid are recommended, but unless you make a really determined effort to go off the beaten track, are not significant risks.
The other advantage is that it is nearly the same time zone AND an overnight flight - so easier to cope with for both you and the kids!
Flights are not the cheapest though (if you hunt, you find them for about £500) - but once you're there everything is dirt cheap as the rand is very undervalued at the moment.
We're just back from a holiday there and our "blow out" meal, in a good restaurant with a bottle of the current top South African wine came to a whole £39 - and that included extra portions of strawberries for ds (who was only 13 months - but it kept him quiet!)
Two nights in the Kruger (in "family" accomodation - ie a rondavel with a twin room plus a bunk bed room, and a kitchenette) cost us a total of £59, with entry into the Kruger coming to less than £10.