Adioma has one of the largest icon collections, with all icons done in one graphic style. This allows you to combine as many icons as you would like in a single infographic.You can choose icons by clicking on any icon on the left or clicking on them right inside the canvas. This icon picker will appear. Here you can either search for icons using keywords you can think of, or browse them by category to see what we have.
If you don't find the icon you are looking for, you can add your own. Here is an article on how to do that http://help.adioma.com/icons/adding-custom-icons The icon upload option looks like this.