i dont really know much about ducks but i agree, the breeds suggested all sound like pretty good breeds and good for you. also i would reccommend checking craigslist, local 4h shows or groups, byc auctions on here, etc, also ask around, someone may know of someone selling or getting rid of their birds or something, and check back reguarly. also some hatcherys may have them, i dont know many hatcherys, but have heard of mcmurray hatchery but im not sure if their good and/or they may just have chickens, i think they have ducks and some other birds too though but not sure. oh and i would also reccomend checking out
www.petfinder.com, its a great website and they have lots of wonderful animals in need of homes, you just enter your area and what type of animal (dog, cat, bird, horse, farm animals, small & furry, etc) and it shows you lots of animals in need of homes and you can narrow the search down by size, age, gender, etc and/or you can enter a certain breed or type too (so for instance for dogs id choose dog, enter Labrador Retriever or retrever in the box then enter my location and it would show me all the labs or retriever type dogs near me, then i could further narrow it down by the above mentioned charicteristics), its a great website you should try it. and i dont know about you but near me there have been known to be at least a few ducks listed, not so much chickens (they have some, mostly roos and stuff though), but they do have ducks so i would reccommend you check it out as well as all the other places mentioned. you could also google it (the ducks) and/or search for local breeders to find out more about them and/or find some in your area. good luck!
*edited for spelling*