It really just depends on what you want to accomplish. A blog can help you provide valuable content to your readers. As they start to follow your blog and read your content and like it, they will start using your services.
If you don't want to spend a lot of time writing on a blog or providing content to maintain your blog, I would go the website route.
You will have to find some methods you can use to promote your website. A blog can help you promote your website by providing SEO optimized content and over time start ranking.
Of course ranking won't happen for a while. It takes a lot of time to start seeing organic rankings in Google.
So the answer is it depends on how you want to promote your business and what your goals are.