Se Asia it is then.
do take into account the time to get over jet lag, 12 days is pretty short to deal with 6 hrs plus of time difference.
If at all seriously interested in biking in SE Asian countries, look up recent trip journals on Crazy guy on a bike, where searching for a given country will give you more insight into riding in x country, including real cyclists views on traffic and whatnot.
General take I've seen is that no need to take camping gear, and accommodation and food is inexpensive, outweighed by sometimes wackadoodle driving from folks.
Crazy guy is a great resource for good solid info, I used it a lot researching trips in Mexico and Central America.
As an aside, Southern Mexico and non touristy areas were really neat riding through and people very friendly.
As someone who has toured a fair amount, I'd just add to be realistic about both of your riding comfort zone around traffic and being both calm yet fast reacting to potential dangerous traffic situations.

Have fun planning.