Take a look at the 1/200 scale herpa models, they are simply astounding in their quality. They are extremely accurate reproductions - they use cad/cam to create the molds. The detail is fantastic - and the quality far better thna you could achieve with a plastic model that was painted and decaled. These models are expensive, but worth it in my opinion.
I'm not a fan of the 1/500 scale herpas, they are too small and hideously scaled in some aspects (check out the undercarriage!) and for the most part bear a vague resemblance to the original.