Hi jomyoot,
Just wanted to tell you that buying from Chii Fei is a great option. I live in Bangkok as well, and I had been looking for a rangefinder for a while. I emailed him and he called me within minutes to discuss my needs. Very friendly and helpful, I told him that I needed a R3M and a 40 1.4 within a week before I left on assignment. I was concerned that customs would stop the package, so he arranged to send the camera with a friend from Singapore to Bangkok. Within days I had the camera which works perfectly and I wouldn't hesitate to buy from him again, maybe when the R4 comes out.
As for repairs, I would think that guys like Mana at AV and Eddie at CC have enough experience with manual cameras to fix small problems. My camera is also under warranty for a year so I'm not too worried about things breaking. Hope this helps.