There are not that many vacancies advertised online, so your best chance is to jump on a plane and come look for yourself. You might want to go for schools that already have westerners working for them, since these schools should know how to obtain the required work permit. With your qualifications you should have good chances of finding a job fairly quickly, but be aware that most schools look for native english speakers (especially in the better paid positions).
In Laos the employer will often judge you by the way you dress. So I'd recommend you always wear suit and tie, when you visit schools. Also don't forget to smile
I wish you best of luck with your job hunt in Vientiane