It's interesting to read about your initiative. I am not totally surprised by the desinterest that you came across. The donor community by and large waits for the fires to return only then to throw more money at the flames.
On the other hand, I am not too sure that removing debris is the solution. There are well tested zero-burning techniques. These are economically viable in Malaysia, but not in Indonesia. So, the companies have more interest in just burning the lot. Quick, cheap and dirty.
Over the last few years I have been doing research into who is funding these fires. It so turns out that many European, US and Asian banks are financing Indonesia's plantation company expansion plans!
Ironically, these banks are often based in Singapore, so in the end, the financial staff there gets what it provides the money for.
In short, you might want to try HSBC in Singapore, or some other well known bank, Citicorp or any other: most of them are funding Sinar Mas, Raja Garuda Mas, Astra etc. etc.
The chances of success (of raising funds) may be limited, but by contacting these banks with the story you might actually help prevent forest fires too, on the somewhat longer run,