The millenium environment and Cyclorama are props that use inside Poser and they are relatively cheap.

I use them quite a lot but I also use Vue 5I but if you're worried about cost that wouldn't be a good thing for you, if costs are limited and believe me I know what you mean, then the ME or Cyclorama would be your best bet!

Hope that helps!

Injustice will be avenged.
Cofiwch Dryweryn.