A plethora of round headlight options exist, ranging from taking one off another bike to buying new from the aftermarket. Side-mount lights usually work in conjunction with mounts that clamp on the forks. Stud-mount lights usually require making a bracket that bolts to triple tree. There really are now model-specific "kits". Mounting and wiring is usually too simple to justify specialized kits. Wander around any collection of naked motorcycles, especially older models, and do a bit of studying. You'll figure it out.