Solo on foot, how and where?

I'm going to be in Thailand and Malaysia for 4 months, April to the end of July. After that since I'm already on the other side of the world I have this urge to just go on a crazy adventure. At this point I would have my 40L bag, laptop, camera and maybe $1000 to invest in gear and food on the way and a credit card for my flight home.

I love to film and document my travel, I'll be doing this in Malaysia too on my YouTube channel. I'd love to overland a country mostly on foot but I'm open to the odd bus but I think it would be a very humbling experience and great to film.

Has anyone done this before? I'm thinking maybe a month overland would be solid but I could keep going if I felt. What gear would I need? Risks, like theft, death, environmental stuff? Could you recommend a country down near SEA, (China, India?)

Thanks so much for any thoughts or insights on the matter.

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