Here is the model I use for my animations. I don’t know how to convert Blender files to Poser, though:

http://www.rgbabes.com/amg/Figure.blend

cant help you with that , hope more replies come , cause i'd love to know

You will need to begin exporting the object as a wavefront file (OBJ).

You can rig inside Blender.  Someone has a script for that
http://www.blenderartists.org

http://blenderartists.org/forum/showthread.php?t=121700

A little closer to home there is www.renderosity.com/mod/forumpro/showthread.php the script exports a .cr2 from Blender.

I don't have it, but from testing the samples the resulting .cr2 files work fairly well in D|S but require some adjusting in Poser. However it does provide a way to create exportable Poser format figures in Blender so it's a +1.

o.k., keep us posted on the conversion of your tifa model, 3dbabes. a wavefront.obj file will suffice, as some of these experts can easily rig it with the standard poser joint hierarchy in poser 7 or 8.

The OBJ file can be rigged in any other software too...

I've rigged from Blender, via Poser.  Best way I've found is to "cut" the model into separate OBJ files for each body part and combine the collection within Poser.  Otherwise, you run into Blender's poor handling of vertex groups in the OBJ.

Of course if you really don't need to use Poser, you can -- as was pointed out -- rig in Blender.  But I've never gone down that path since I target my models for Poser.