Standard mice and keyboards that come with a computer system are okay for some people; however, to get a true ergonomic setup a specialty keyboard and mouse is required.
For keyboards some options Ergonomists suggest are a mouse friendly keyboard that puts the number keys on the opposite side or keyboard that does not have number keys. A more go-to ergonomic item is a split keyboard so the elbows are more in line with the body.
For Mice, some options various angles to provide maximum comfort and some while some vertical and others have slight angles to them. Mice come in various sizes and are definitely a personal choice.