Sure, there are hundreds of SEO companies available for you to choose from. Cheap ones that say they submit your site to 1000's of engines (big deal), ones that add 100's of doorway pages (look out for spam), those that promise fast top rankings (they lie). Let's face it, for SEO there is The Good, The Bad and The Ugly. But lets not focus on the bad and ugly....they may be cheap, but you get what you pay for...nothing!
SEO is not instant, not any more. You need to look at many factors, you need to be prepared to make changes, you need to be willing to work closely with your SEO expert and be willing to be in it for the long haul. SEO changes and you need to be ready to meet those changes.
You should be serious about your web site. This is your business and you need to treat it as so. Canned web sites, website templates that offer everything from stores to products to hosting and say you have no worries on updating the site and still can achieve rankings may be a bit misleading. SEO is ongoing work and one you need to be prepared to handle.
Your SEO Expert serves two purposes...to guide you in changes that you need to make to a web site and to help you optimize your web site by actually working within the site so that you can be found for relevant keyword phrases.
Your Web Site Design
It used to be that design aspects really did not matter. Well, now they do and it is a big deal. If your site is poorly designed, poorly coded and developed using complex databases or heavily graphic, you face issues. You may need to make changes, you may want to develop a new site...whatever the need, your SEO will inform you what issues may be causing the site from being read correctly.