The biggest problem is likely going to be to keep it critter proof. Most suburbs have raccoons, possums, rats, etc. all who would be attracted to fruit and veggie scraps. Or even just dogs interested in the smells. So you'll likely need something with a locking lid and heavy enough not to be knocked over. Or possibly something mounted or securely attached to a pole or fence post. Shouldn't be to hard to sink a mailbox post or short fence post in one of the spots you mentioned so you have something to attach the container to.
You might go with a two part system. Something larger, heavier, able to be attached to a post or pole, and with a latch to keep critters out. Then inside some simple plastic buckets or a couple of small trash cans. Something that you can easily pick up out of the more permanent structure, carry to the chickens, rinse out and return.
A small deck storage box could work as your outer box. Wood ones could be painted something with something fun or chicken related. Resin or
plasticones might be easier to clean from the food spills, messes that will happen.
Look for outdoor storage bins. They come on all shapes and sizes. Some are more decorative others more basic. Some are pretty fancy and expensive others less so.
storage column
Try searching for sand and salt storage bins.
sand and salt storage bin
Or these
food waste bin might be just the thing. They already come with a mounting system so you could attach them to a fence post. And come in attractive colors. Not sure how critter proof they are but if they were attached to a post and up off the ground enough to be out of easy reach it might help. There are lots of other food scrap bins out there and some larger sized ones have mounting brackets so you can attach them to a cabinet door (or outdoor post in your case). I could see a fence post (maybe painted a fun color) with your sign mounted on the front explaining what it is. Then one or two of these larger sized bins mounted on either side or under the sign. It might come of more as quirky yard art than eyesore.