We live in the cut and paste era, with a huge availability of pictures, charts and icons.
Still what you exactly need to picture your message may not exist yet. According to your time, skills (or hire a pro) and budget try to have the visual elements you want.
Stock pictures tend to be cold and not necessary are what you are looking for precisely. At times it’s better to produce your own photo, albeit less professional, than to use a ready one. Same it goes for other graphical elements!