A pretty website is only part of it, I think you need to show the business owner the competitive disadvantage at not having an online presence. Even if you are not a SEO professional, you should include some SEO work for the site.
Although I am not in the business if I was going for a personalized approach, I would also include a preliminary keyword position summary. You can throw in some data about the number of searches per keyword, and the percentage of people that click per position to show how many leads they might be missing. Do not oversell it because most people can smell BS a mile away, but make a reasonable argument.
I also know that there might be some purists that might take the position that a designer is a designer and not an SEO expert, but for a small unsophisticated customer you need to present a complete solution.