Lao, Burmese, Khmer Teachers In Bangkok?

I am settling into a new 'academic' life in BKK after joining the MA in Thai Studies course at Chulalongkorn University. This course requires 3 half-days per week, and I have little else to do in my spare time!

I have a great interest in languages, (I speak/write reasonable French, German, Italian, Spanish, Flemish and of course Thai!). So, since I am in BKK for at least the next 18 months, I would love to put my time to good use by learning conversational spoken/written Burmese, Lao and Khmer (Kamen).

(I already understand spoken Issan Lao - my wife is from Sakon Nakon).

But how to find a 1-to-1 language teacher in BKK? I don't want to spend my days hanging around the building sites in BKK, (where there are many foreign workers).

I have various teach yourself books. But that will not help me to grasp the intricacies of the spoken language.

Any suggestions as to how I can locate teachers? (A Google search has not located any resource).

Thanks

Simon