SoCal-chick,
You asked about the feeder I put together. It's really simple in that, at the bottom of the bin (or silo) , instead of it having a flat bottom, I installed a slanted floor which "funnels" the feed down to a slit, maybe one inch in height, that empties out onto a feeding shelf. The feed shelf has a 2"x2" ledge to keep the feed from pouring over onto the ground, and its only big enough for them to get their little heads into, maybe 4-5" front to back and 16" across. In this way, as they feed from the 4-5" shelf, the feed drops down out of the shute and onto their shelf... sorta the same principle as a waterer, where, when the water gets low enough in the dish, a bubble goes up in the reservoir and a corresponding amount of water lets down into the dish.
If you can keep your water inside, I think that's best because summertime sun/heat really enhances the growth of bacteria, and during the winter, it doesn't freeze as readily inside, although in your climate that probably isn't an issue. If you try to keep your water inside, your only problem would probably be keeping it out from under the roost, and keeping your flooring dry.
Good luck-Spence