Just for your information, phoenix worm (at least the one you get from the store) should not be fed poop or trash by the provider. Naturally, they eat some vegetables matter. Phoenix worm is quite different than house fly maggots. As far as nutrition, phoenix worm seems to have a somewhat "better" ratio than silkies. BUT, the fact is Phoenix worm can pass through your chameleon system without being properly digested. Also, some chameleons are finicky about size. I know my adult panthers won't eat anything smaller than crickets. So, he usually ignores those phoenix worms.
With that said, I am more in favor of silkworms than Phoenix worms.
But, it doesn't mean that you cannot feed your cham with phoenix worms. Provided that your cham will eat them, I say go ahead and buy both.
The more variety of insects you give to your chameleon, the better his health and the happier your chameleon will be.
I let everyone else answered about the supplements, but as far as greens goes:
Kale, collard greens, Hibiscus leaves and flowers, and
Dandelion leaves and the flowers (available sometimes at your local albertson or your Local Korean Market) are all great choice. I put dandelion in bold because Dandelion is arguably one of the healthiest vegetable you can give him (you can actually eat it too, if you want. It is very good for you also)
Avoid tomato and potato leaves (poisonous), broccoli, rhubarb, and spinach (they contain oxalates that can block calcium absorption)
Make sure you washed those vegetables very thorough to remove traces of fertilizers and pesticides.
