You might consider using the Poser Collada export, and reduce the texture maps size in that proces. That's what I've been doing lately, works like a dream, much less resource drop etc. You'll have to tweak the textures a little to make them look good in Vue (bump, specular) but that's needed in most cases anyway.

If you want to repose your characters inside Vue, maybe consider setting up the lot in Daz Studio instead. Then you can import the Collada as a rigged, posable mesh into Vue without the Poser dynamics hosting problems.