Yes, as they are all the same species. You should avoid doing something such as breeding a Jersey Giant to an Bantam Cochin, but overall any chickens can breed with eachother. You may get some with beards, some with crests, some with both, some with none. FUN.
Your Polish roo is smaller than your Ameraucana?
I want to get true Ameraucana's, too, and am planning on getting some in the spring from BYC members. Many people here are very good breeders who are proud to sell you REAL Ameraucanas. Not that I don't love my EE and OE, but I do want a few of those gorgeous blue-egg laying birds.