You know what? Showing poultry is fun and it is a good safe family activity. So take them and show them.
I don't know enough about Polish to say if they can win, but I can see that they are at least good enough that you won't be laughed out of the barn.
You can go, have a very good time, and talk to some serious breeders of Polish who will talk your ears off about what features to look for. You'll have the opportunity to learn a lot.
Then if you really enjoy the showing and it turns out your birds are not Grand Champions, you can make arrangements at the show to purchase some serious show potential birds.
Or who knows, you might be walking around the show and come face to face with your heart breed. You'll know it if it happens. Your heart goes "Twang" when you look at them. Then you can make arrangements to purchase some birds or chicks of that breed.