You would be better to buy poser 6 because it is the newest version but it does use more memory than poser 5 and poser 4. I have poser 5 and poser 4 propack installed I use propack for making figures and anything else that I don`t need poser 5 for. Poser 6 would be the best to get but keep poser 4 on your computer, at least till you have used poser 6 for a while.