For an online business, a detailed and in depth business plan is usually not necessary unless you are trying to combine your online business with a traditional business. For most online business startups, the detail involved with planning a traditional business is not required. However, it would still be beneficial to you if most of the topics were still covered, even if only briefly. Having a written plan in front of you will help you to focus on important aspects of the business.
I don't know of better way than to let your business give you what you want for your lifestyle. Whether it's a sample business plan for a small business or one where your business gives you a plan, it should tell you what is needed to take you where you want to go and when and how you can get there and it should be in clear simple terms, supported with all the specifics. So using a sample business plan for a small business is just one of many ways to make a business plan but frankly I think designing one that will have your business give you exactly what you want is by far the best way.