I'm sure you should be able to get something going with Poser 9, especially if you add more memory. My old and cranky machine can handle PP2012 fairly well to set up most scenes and render the simpler stuff. It can't render any massive sized scenes with lots of SSS and other fun stuff so those have to go off to my big render-beastie instead, but I actually prefer working on my old machine as much as possible.

So I guess it depends on what you actually want/need Poser 9 to be able to do, as to whether your machine can do it. If that makes any sense! :)