Hi, I have written a blog post regarding domain names. Choosing the right domain name is crucial and can affect your search engine rankings/SERPs. Read it here: http://www.tw3o.com/2007/05/25/choosing-the-right-domain-name/
It is always good to have a good domain name for your business, but even if you do not have one there are plenty of other options on which you can focus for SEO.
Most of my clients want there business name as the domain name but it is not always the best option. I recommend taking the business name and 301 to a more suitable domain name. Choosing a difficult to remember/type in domain name could cost you.