I have read that male and male do fine, male and female do fine, but you usually have more problems with 2 females. I have no idea how true this is.
Females.....that's another matter, at least with my breed. Some just ain't going for another Queen around (like mine). I have two females right now that cannot even be aloud to see each other. Not fun!
I also wanted to add that I agree with OC. That is the way I introduce my dogs to new rescues and it works 99% of the time.
Good luck, I really hope you get him.