A good majority of Jessica and Sydney clothing can be found @ runtimedna.com and contentparadise.com.  Unfortunately, there isn't a huge selection unlike the DAZ millennium models.

Conforming clothing is designed to fit and bend with a specific figure, it cannot be shared between figures withoug additional work. The clothing is divided into body-part groups and these body-part groups use the same conventional names as those in the underlying figure.  When you 'conform', the groups in the conforming clothing mirror the setings of their corresponding counterparts in the figure.  When posing your figure, the conforming clothing automatically follows the same pose.

Dynamic clothing is a prop, typically found in your Props Library.  They are parented to your figure, and if you want to clothe your figure then you must apply them in the Cloth Room.  Therefore, you need to clothify the prop to make it move with figure, thus dressing your figure.  In essence, what you are doing is creating an animation to use dynamic clothing.