The two main places I've gotten both Moringa and Leuceana seeda from are ECHO Seedbank
www.echonet.org, and from the folks at World Hunger Relief
www.worldhungerrelief.org. I've noticed Moringa seeds are easier to find with several other online sources such as seedman.com, or even eBay.com. Shop around though, and of course bulk is always less expensive.
I start seeds in March or April inside. They get transplanted out when seedlings are between 6" and 12" tall - around May. I am going to try propagating from cuttings this year.
Note that both of these plants are going to do best in more southern locations - I've seen them doing well up near Dallas, TX, but I am not sure how much further north they will be useful, unless in a greenhouse situation of course. BTW, I believe that greenhouses are a critical element to almost every food production system regardless of where you are. Every bio-region has different reasons why to use greenhouses. While researching sustainable living in Central America I was stunned to see how much they used green houses -
to keep the water off the gardens. Greenshouses are not a sustainable forever technology, but there is a ton of old sliding glass doors (made of safety glass) available to use for a long time.
I am looking forward to living in a colder climate so I can explore plants, animals, and strategies specifically for growing in those conditions, but that is another project..
Always on the lookout for good home businesses, I think propagating both leuceana and mornnga is a niche where you could do well. Useful or food producing plants is a good business overall.
Marjory