Shade or Wings will do. See if you can at least grab the arms and move them up. That'll make rigging a bit easier. From the looks of it, the only spot that will really bend smoothly is the inner elbow....for everything else, turn off bending first thing. As long as you have bending turned off the fact that this model is really a bunch of unlinked primitives will not be a big problem. Creating groups in Poser would be difficult for this one. With any luck the original model or even your conversion has different poly groups for all the little technical bits. Your best bet in any case is to set up your groups outside Poser. Again, try Wings or Shade for that task.