Buy business web template with total customization option. You may get layouts in the market designed superbly but with little scope of customization. On the other hand if you go for open source developments like the Drupal, Joomla or others then you should buy layouts designed for particular themes. Otherwise your developers or the designers will face problem to make layouts completely fit for your business. Even in SEO related changes there will be problem.
Because newsletter templates are available in all variety of lengths and sizes, there is really no limit to the content that you could potentially write. Keep in mind, however, that you should probably keep down your word count to a level that people are comfortable reading. While you may think everything that you are spouting off is fascinating, it's helpful to first sit down and make an outline of what you want your main message to be, or what the major news is that you are trying to share.