I havent been in 4-H in 50 years, but from what I see in shows, the more unusual breeds get lots of attention. If you can get a copy of Poultry Press, many quality show breeders advertize there. Start with the best you can get. Hatchery birds are never show quality.
Any of them. You will have a lot of fun showing those. In our county you can enter showmanship with one of those which you will be judged then you can show each of those birds and they will be judged with among the other birds in their class. Start learning poultry parts, the care of your birds and about each of those birds.