I understand where you are coming from... I really wanted to stick with Anconas when I first got ducks this spring. They are not a really common breed, and while I don't intend to breed for show, I'd still like to have kept to just that breed if possible.
But it just hasn't worked out. I had a bad ratio of males to females, and nobody seems to have Ancona hens available. What I was able to find were some free ducklings from a friend we know, and that gives me the chance for a few more girls. I took them, because I know having a few more birds with a better ratio will give all my birds a better quality of life. I think that matters more for me with a small flock of ducks, that they are happy.
And like another person said, I intend to separate out my Ancona hen with an Ancona drake in the event I do decide to breed them. Easy enough to do, and you might find the same when you do decide it's time to hatch WH babies.