I know they're together/related....just not sure which is which. Yeah, DS only does LF.
Just meant to reassure they'll actually be Ameraucanas and not EEs, so you shouldn't have any worries on that front. Getting DQed really stinks for kids, especially when they're just starting out and usually have very few birds as it is.
For the bantam: get yourself a d'uccle and raise it from a chick. They are total sweethearts if handled daily and like being petted if treated gently from day 1. For the large fowl. Try a Langshan. They seem very calm and not flighty, but do get big. I've heard brahmas are good large fowl for kids too, in addition to the favorelles.
I think any breed is ok, as long as it is one with a calm demeanor. Some breeds are known to be flightier than others, most of the Medditeranean breeds. Try and go for a calm breed, and have the kids handle them a lot from new chicks on up.
The pp who mentioned smaller birds for showmanship, gave you good advice. If they are going to do showmanship, they need to be able to hold the bird, spread the wing, flip it over and show the judge the keel bone. Having a smaller bird makes some of these tasks much easier for the kids, especially if they are just starting out. Having a big heavy bird will make it more difficult. So if you are sure you want a LF for your older child, try and find a "smaller" large fowl. And maybe have them use a pullet or hen instead of a roo for showmanship. Not only does the bird need to be used to being handled, it has to stand on a table for a 1/2 an hour or more with other birds right beside it. Sometimes the roosters don't like being next to other roosters and it will be up to your child to keep it under control. Also get your child involved, and let them help pick out a breed they are interested in! Most of all, have fun!
Oh, and make sure each child has a "back-up" bird or two for showmanship. It never fails that their most favorite prized bird will molt at the wrong time or get injured right before a show or some such thing. So if they have a back up they can still participate and not be so disappointed that their main bird wasn't cut out for showing that day.
I always pronounce it like dew clay. Don't know if that's correct, but that's how I say it. I thought I had bought 2 Porcelain ones until my DD wanted to show them and we looked them up in the SOP. That's how we found out we actually had Booted Bantams. Very similar breeds. The Booted Bantams are unbearded and have a different stance/body shape though.
my kids show the bantam wyandottes. Good ones are easy to find and don't cost an arm and a leg. They come in a wide variety of colors. Heck, my 5 year old carries around the young standard roosters until they get too big so they would be a good choice for your older child too, but they can cost a little more.