You don't need Poser, though there's still a lot that D|S won't do that Poser will (magnets for one). Just create a pseudo-Poser folder on you system, such as "Poser content", and install your stuff to that (you will get a Runtime folder in your folder, with sub-folders in that) and in Studio go to Edit>Preferences, the Directories tab, select Poser content directories from the drop-down list, click the Add button and select the folder you made ("Poser content" of whatever).