We have the 3 Mallards from a hatchery and we asked for females. The Rouen we picked up from someone who had no clue whether it's a male or female, so we are waiting to be surprised! I wouldn't mind having a drake...I agree the having babies thing is scary. We were told to just remove the eggs as soon as they are laid and put them in the fridge....voila no babies. I'm not sure how he would react to the 4 hen's (we hope) that we are brooding as well. They have been brought up together in a brooder with hardware cloth between them and are together when we take them outside the brooders and the ducks and chicks basically ignore each other.
There is a formula as to how many square feet per adult duck....can't remember what it is tho. Maybe 10 - 15 square feet per adult duck? Don't quote me on that. I am sure to be corrected by those who have been raising ducks...this is my first time as well. It also depends on how large the breed is. Our enclosure is pretty large, so I haven't worried about it too much.
Anyway, have fun and enjoy those little menaces! I'm afraid to even go to the local fair for fear of coming home with more critters!