julesart, you can use the set you found on ShareCG. Poser does accept 3DS model. 
Just import them as follows;
Click on FILE got to IMPORT and then select 3D STUDIO.
A box comes up with import options. (I like to check place on floor, but don't worry about the options until you are familiar with your itemd and know how you want to manipulate it)
A window opens and you browse to where you have stashed your 3DS item. Select it and click OK. And that's it. Your item will load into Poser.