Terriers tend to be very energetic dogs, both male and female. A lot depends on their breeding. You do need to be very careful about who you buy from.
The YTCA site has some good information about the breed and it's history. There is also some breeder referral information available.
The Yorkshire Terrier Club of America
You can also locate an AKC sanctioned dog club in your state or surrounding states. These clubs are usually quite professional about their breeding practices and have breeder referral people that can point you in the right direction as far as breeders.
American Kennel Club - Club Search and Directory
You can do an all breed conformation club search and also a specialty search. Not all states have a Yorkshire Terrier specialty club but almost all of the all breed conformation clubs will have Yorkshire Terriers. Many times you will pay less for a good pet quality pup from these breeders than you will from most of the scams you find online and in the classified ads.
If you are looking for the right temperament I would not decide according to the sex of the dog. It is more an individual thing. Seeing and handling the pups yourself will give you a good idea of what kind of temperament you are dealing with.