OK, just and FYI...when you are purchasing products at Renderosity and have questions, the first thing to do is open the ReadMe file.  They provide this file for you to read before purchase on the main catalog page, just below the main promo on the right.

However, I have looked at the readme and have a couple of discoveries and suggestions for you:

1.  All the textures are created as .dsf files so there is simply no easy conversion to Poser.  Evidently, this seller has no intention to make any of this easy for you.

2.  There's a folder called:

My LibraryRuntimeTexturesHellFishStudiosSubDragon

which has the texture files you can load in the material room in Poser.  You probably need to copy the folder to your Poser runtime (leave off the "MyLibrary" part).  Of course, since it's a DS file, I can't assure you that all the files you need are there (some may be DS dependent shaders) but it's a starting point.  The seller could have at LEAST told you if all the necessary files were in the folders.

3.  All of the animation files should work as they are standard pz2 files.  The scaling files, however, are probably not going to work at all.

If you need help loading textures in the Material room, let me know and I'll try to help.