Sorry no one has answered you!!
My ducks are all layer/meat types, but they are still wonderful!! They started out with a refrigerator drawer as a pool until they were almost fully feathered. There were 4 in the beginning. They don't need much room, I don't think any moreso than a chicken would. Mine all live freely on the pond, and they do not wander far from it at all. They are not a bit hard to take care of, at least the kinds that I have. As far as if they are expensive, I have 10 ducks that are full grown size-wise and they eat about 50# of flock raiser every 2-3 weeks. That is a bit more than my chickens (per bird), but my chickens are all bantams!
Out of the three breeds that I have, I would recommend the cayugas or the rouens. The pekins are way too loud, and would probably drive your parents nuts!! If you were to get a pair or so for breeding, I would go with the cayugas. They are the best brooders out of the 3 breeds that I have. But I love all my ducks (probably why I have more drakes than ducks!), and wouldn't get rid of them for anything!
Another plus to the breeds that I have is the fact that they can't fly very well. They can fly short distances to evaid predators, but not so much that they will fly into the neighbors yard. Call ducks are the 'bantams' of the duck world, but it is my understanding that they can fly fairly well. The same with muscovies. If you are afraid of the predator problem, muscovies would be a good choice. They fly almost as well as a wild duck would.