If you are new to chicken raising, I'm really not sure I'd recommend planning to not feed at all. Perhaps start with a 50% pellet ration, and work down from there... Apart from the difficulty of setting up a system that offers complete feed, you won't have the familiarity with chickens that gives that esssential "instinct" about what they need and whether they've got it.
Then again, if you are motivated to shoot the moon, I'd hate to be the one to hold you back!
As for guidance, my top favorite chicken guru is Harvey Ussery. He keeps a wonderfully informative website with a whole bunch of chicken articles at http://www.themodernhomestead.us/article/Poultry.html
He also wrote my top favorite chicken book, The Small Scale Poultry Flock. He doesn't bill himself as "permaculture" and because of that I think he doesn't make it onto many folks radar, but he is awesomely integrative. He discusses mixing your own feed, sprouting grains, raising worms and black soldier flies, outdoor forage and protection, as well as winter forage under greenhouses, not to mention all other aspects of chicken raising.
I assume you've seen Geoff Lawton's video about the farm in Vermont that raises chickens on 100% compost? Very inspiring.
I myself thoroughly researched and explored the redworm chicken feed connection a few years ago, and came to the sad conclusion that I simply cannot raise enough worms to make even a significant contribution to my flock's diet. As someone else mentioned, they can eat a lot of worms! And the worms just do not multiply fast enough. I don't have the numbers, but my rough figure was something like a 10x20 foot worm bed to supply my home flock with just their protein requirement. It does sound like you have lots of land to work with though, and a mild climate (I just have a yard, and live in Alaska, so I would have to keep them in a heated shed). Check out the article I wrote for PRI on turning a portion of my coop bedding into a worm farm-- there are some good links at the bottom--
But, like the other responders have said, you don't want to feed them just worms anyway. You will want to plant a Chicken Guild-- with lots of comfrey, dandelions, nettles, dock, lambsquarter, quinoa, grain grasses, fodder radish and turnips, probably all centered around a mulberry tree, and with deep mulch and a few compost piles around to breed invertebrates of all kinds.
Good luck, and enjoy the puzzle!