"Service kit" is a bit elastic, for minor service it's oil, and clean air filter if needed, the rest of it is checking, adjusting and lubricating. Major services include plugs, air filter, oil, oil filter etc.
Best thing is to read through what you need and make a list, then it's really no harder handing list to your local bike shop than picking up a bike specific kit, think of it as a customised kit to your requirements
