It all depends on the temperament of your dog and the one that you want to get.
It makes no difference whatsoever if a dog is spayed or neutered when it comes to the temperament of a dog! The only
difference is a male that is intact will become more aggressive only
when their is a female in heat near him. And that only
happens when there is another intact male near him.
If your dog doesn't like other females then get a male. If your dog likes other females and you find another female that likes other females then get a female.
In any case, get any dog that your female will get along with and be sure that the two dogs will get along with each other.
Just curious, why do you want to get another spayed female? Why not a neutered male?
I hope this helps.