I am just going off of what I read...no personal experience here. Here is a little bit of what I found...
1. Choose a puppy of the opposite sex. Even among neutered dogs, same-sex disagreements or rivalries are far more common than opposite-sex ones.
That comes from
Anything we should know about introducing a new puppy to our current dog? | Ask Metafilter
2. That being said, as far as male or female....again, in very general terms, a male and female tend to get along better, and then 2 males. Last of all, two females...Again, there are many varying factors, so I would really not spend a great deal of time over this.
This is what I read, but can't find the exact link to. It said something about male-female being the best combo, male-male was not as good, and female-female is the worst. This came from
? regarding adding puppy and other dogs in house.
I am sure it would be fine, I just wanted to give you a heads up about possible dominance issues.