Patents: Redesign an Exsisting Product

Hi, I would like to re-design an existing product. This is an extremely common household decorative item and these have been re-designed and sold thousands of times over the years. So now I have thought of a design I would like, though I'm not sure if there has been "prior art" of this particular design I want to do. Could you please tell me whats involved and what steps I should take? My design would be completely different. Same use but different design.
If I were to pursue this would I be needing a design patent or improvement patent or what?
I would appreciate your thoughts and advice.

Thanks, Leann

Patents: Redesign an Exsisting Product