You should not have a problem. I personally kept a flock of
male Gouldians with no problems at all. They would often do
their little dance for each other and sang beautifully.
I know many people keeping just males (or, to a lesser
extent, just females. *females do fine together too, just I
guess they are not as pretty so most that I know chose
males) Their colors are stunning and their songs are
beautiful. Their courtship could be described as comical.
Gould's are gentle and peaceful birds. (Though, I have been
told that they will occasionally pick on other's to defend
their nest if bred in a community setting.)
So, assuming that your cage is large enough to comfortably
house two Gould's, I'd say go for it. They are much better
off with each other then alone.
I personally never kept females with my boys cause I did not
want the hassle of breeding (with their tendancy to not
incubate the eggs or not rear the young if they hatch).
They are great birds. I find my boys where quite curious
once they settled in. They always be excited when food was
comming and if I talked to them my favorite little orange
head would fluff and ruffle his feathers.