University of Hawaii CTAHR is the best place to find organic seeds. They also have a wealth of information online about gardening in Hawaii. Also, I might suggest taking walks through one of the many community gardens in Honolulu to see what and how things grow here. I have a plot at the Mamoa garden that I'm slowly getting up and running. I've learned so much just from observing everyone else's practices. I'm sure you'll be happy to know that kale and chard grow magnificently here as do many types of lettuces. There's this "miracle" green called kalamungay that I'm dying to start growing. It's native to the Philipines but grows very well here. I think you'll find gardening in Hawaii very rewarding. Three words - year-round gardening!