My son, brother and I are planning a trip to Thailand and Cambodia in July or August of 2015. We plan to stay eight days in country. Tentatively, we're thinking of Bangkok, Chiang Mai, and Siem Reap (Angkor Wat) with connections by air. However, we're flexible. Any city, hotel, restaurant, tour recommendations, or other travel insight would be greatly appreciated.

I spent some time in Bangkok, Korat, and N.E. Thailand 40+ years ago. However, I never made it to Northern Thailand or Cambodia. In addition, I expect that today's Thailand is much different than the one I experienced.
 

I didn't find the right solution from the internet.
References:

https://www.bogleheads.org/forum/viewtopic.php?t=146191

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