Build a Wordpress site > Convert from Dreamweaver

Background: I have a very small B2B client with a simple 5 page site built in dreamweaver > no CMS. I want to upgrade them to a Wordpress site so I can manage the content. Theme TBD The goal of the re-design is to make the business look larger and more professional. The target audience is a vertical VP Marketing. Requirements: I think it makes the most sense to build a new site from scratch, but not sure how that impacts SEO. I expect the new site launch to have between 20 - 25 pages of content. Content is not written yet, but will start next week and the goal is to have it all ready to hand over to the web designer in ~2 weeks. Images, color palate, nav structure and content will be provided, but I would prefer a collaborative approach on selecting the best theme etc....as this site will be essentially new. Client is frugal, so using available WP tools to maximize visibility is a must. Google tracking should be on all pages, keyword tags etc.... We may also need help moving the files from their staging location to the ip address. They have people on site but I don't have a lot of confidence. Longer term the site will/should have a blog but we will have content ready for the site re-design launch. We also need a landing page or two for scheduled direct mail and email offers. Extra: I would like someone who could also help with keyword research. Not required but it would be nice if it was the same person. Tamara