Looking for NGO work and wanting to settle in Cambodia

Hi, my wife and I are South Africans, I'm 35 and she's 28. We are currently farming in New Zealand but are longing for the challenges of the developing world so decided to sell up and head for Cambodia in December this year. I have a four year degree in Agriculture and mixed farming experience in Africa, Australia and New Zealand and I also have a post graduate certificate in Education and have taught at high school level for 5 years as well as having done 3 months volunteer teaching in Phnom Penh in 2009. My wife has a partially completed degree but wants to do a tefl course to teach English. My questions are as follows:
a) will I be able to find a job in Cambodia doing agricultural development work that will allow my wife and I to sustain a living there? I have stayed in many of the villages there on my previous stays and my wife and I are real bush babies and don't mind "roughing it".
B) alternatively are there many sustainable teaching jobs in Cambodia.

We will only have a total of about 5000 dollars to land and keep us going until we find something, is this possible and advisable? Any advice and tips will be invaluable to us. Our e-mail is [email protected]. Thank you in advance, Roy and Candice