[GoHokiesGo]

I'd probably recommend similar to everyone else - the 35 and 85, and I'd probably have the 35 on my camera most of the time since it serves as a good all-around focal length.

Honestly, I'd really think that you would want something wider too, even though you mention landscape being a bit further down your list; however, there are some pretty incredible landscapes and scenes in throughout the temples and beaches in both countries. The clouds during golden hours in Thailand are breath-taking.

Where are you going in both countries? More beaches and temples, or BKK city and street life?