I just could not decide on just one breed (those darned focus threads again!) so I'm getting a mix: Pekin, Buff, Welsh Harlequin, 2 Khaki Campbell, 2 Blue Indian Runners, Blue Swedish, Cayuga, and a white hybrid. The Pekins do get bigger than the others but I'm hoping since they'll be raised together and the Pekins are supposed to be calm birds, that they'll do ok as one flock. I was able to request all females with the exception of the WH (they are unsexed at the hatchery I ordered from) so if I end up with just 1 male that's fine.
It's hard to narrow down breeds, whether you're looking at ducks or chickens, but it's fun!