Do these look like a male and female or 2 males.

[Isaac 0]

Two Drakes.

 

[Zeddemore]

If I can get the wife on board to get a few female ducks what would be a good number to go with the males?

 

[chickens really]

6 to 8 Hens and even then you might need to get rid of one Drake...Breeding season is aggressive in Ducks...Drakes fight...

 

[The Moonshiner]

I don't think you'll have problems with just two drakes. I always keep at least two in my groups in case one isn't doing his job or if something was to happen to one it's good to have a backup.
I never had a problem with drakes fighting but the breeding was a problem when we had many drakes together. When one drake breeds a duck then every drake lines up and breeds her then at times the drakes would also breed each other. They are nuts. 6 to 8 or even more would work for two drakes.