If you are going for small it may be better to go for cochins instead of brahmas, as you keep the fairly small comb and leg feathering but lose the giant size.
I may be wrong, but I thought that 'breed true' means that if you cross it with another chicken of the same type, the chicks would hatch out the same breed and color? It is my understanding that the color black breeds true, while the color blue does not.