Any of the quality Western mattresses.
Thais are generally light, so mattresses with less strength suit them just fine. Also, they tend to be younger (than us old guys) and fitter.
I've found that losing weight, drinking less and exercising is helpful. I also purchased one of those super heavy American mattress a few years back. Lovely to sleep on.
What I don't like at all are thosw super expensive foam mattresses.