new bird

Hi I am new at this - the notes and the birds as well. We have an outdoor aviary and 8 birds in it. Bought them from a breeder locally. We bought some nesting boxes but do not have any breeding cages. Are they necessary? I would like to really record and experiment with bird genetics but my husband just wants to see them flying. Do we get a block of breeding cages that is big enough for our 4 pair, or do we assume that we will have some good ones to breed with later and get a bigger block? So far, none of the birds looks like being interested in the breeding boxes. Should we worry? This all sounds SO amateur. Sorry.