Rural House with Yard & Fence

My first cousin is looking at moving to Việt Nam.

He's a 70 year old American citizen living in Thailand the past seven years on social security. 

He prefers being about 10km or more away from cities.

He wants the yard and fence primarily for his dogs.

He has been renting a house in Thailand for about $150 USD a month, though he can probably afford  ₫5,000,000+ VND

He doesn't need the beach, though he wouldn't turn it down.

Only looking for general area recommendations  right now, to start searching for him, anywhere in the country.

My Vietnamese domestic partner will be doing the groundwork for him.

Thanks for any constructive suggestions.

Does he have his own furniture or will he buy it when he arrives.

I would try anywhere in the Mekong Delta, it's cheap and quiet.