Just an update:

On the Vue forums, I've seen reference to a tutorial about importing Poser items into Vue which has some valuable information about reducing texture sizes:

http://www.silverblades-suitcase.com/tutorials/htm/18.html

Well worth the read as it's put my mind at rest about duplicating textures, etc.

Many thanks to all for your valuable insights

Vue Easel here I come (when my credit card has cooled down!)