Picons offers a number of Icon sets that are hand-crafted and available in a number of formats, most importantly as native .Sketch file.
Their line icons are fully customizable. You can make the stroke thinner, thicker or even dashed. Change the size, shape, color and orientation in just seconds. Icon sets also work with IconJar.
You can purchase individual icon sets (Thin, Basic, BasiColor, Font, Weather, Social) or save money by getting their “Complete” package at a discounted price.