Can you post your image so we can see?

I get my cues by watching the render happen, and see where in the image it starts getting hung-up. Hair, as well as eyes seem to be slug-it-out times depending on what type of shader setting was used.

So, I'd watch the render next time, see where it starts stuttering, then see what shader settings were used on that part, and maybe re-adjust that shader to be more Poser 4 friendly.

As for getting the effect you want in Firefly, thats why a image post to reference would help.

Carrara 7 Pro, Anime Studio Pro 8, Hexagon 2.5, Zbrush 4.6, trueSpace 7.6, and Corel Draw X3. Manga Studio 4EX, Open Canvas 5, WACOM Cintiq 12WX User