My wife wants to make 38"x28.5" prints from her oil on panel paintings that are 16"x12". I have enough experience with non-digital SLR photography to know that the hardest part of photographing these works will be the lighting - however, that's not my question.
As I understand it (correct me if I'm wrong) image sensor format (Medium Format, ASP-H, ASP-C, Four-Thirds System, not number of megapixels) greatly affects price point, noise level, lens distortion, and lens price.
She's going to buy a camera to document her oil-on-panel work and to make prints. The camera isn't going to be used for anything else. She would like to know what is the most efficient use of money for her problem space, assuming she only needs a camera and a lens? What image sensor format should she consider / avoid given this problem space? Should she spend more money on the camera or on the lens - or are they equally important given this problem space?