kelly, that visa restriction will be removed in a maximum of two years, once he gets his ILR.
and YOU, as a British national, can claim benefits on behalf of yourself and your children, who are British nationals by right of having you as a British mother.
you are already getting Child Benefit for them.
you can get housing and council tax benefit, too, if you qualify for it as a British national and they will take into consideration your British children.
he is not allowed to apply for it in his own right, but you can claim it and have him on the app (you'll have to because you are married) and explain his immigration status.
they will ask for his passport adn the like, but you can claim them.
the only immigrants who can claim as such are a) asylum seekers, and they are not permitted to work by law b) EU/EEA nationals who have been in the UK for 12 months or greater c) are on ILR or some other, non-time-restricted visa.
i am a naturalised Brit myself.