Planning a similar trip myself, but probably in 2010.
Some suggestions on whom you might ask:
- Thai Flying Club, who seem to have a good deal of info on SE Asia
THAI FLYING CLUB - General Aviation and Sport Flying in Thailand - AOPA THAILAND
- AOPA Greece has good info on their website
AOPA Hellas | Aircraft Owners and Pilot Association of Hellas
see bottom of the page "Flying in Greece - Useful information"