Change Website from Table to Divs & Visual Upgrade

Part 1: Our entire website is setup inside of a table and I want it to be setup inside of DIVs instead. There are approximately 700 pages, but they are dynamically being pulled from about 50 actual pages. I would like only a few CSS files to dynamically handle the entire site. We have thorough documentation of how the site is constructed, we have a support forum for additional help, and senior web designers who can give assistance. Part 2: We have 3 different parts of our website. Each have their own look and feel to them. We want an overall theme that is the same throughout the entire site. You may see the sites here: [login to view URL] [login to view URL] [login to view URL] We would prefer if all 3 sections are visually identical so users will feel comfortable going back and forth from one to another. Links among the pages should easily take a user back & forth between each section. We already have all the programming done on these, but now we want to front-end of the website to look more visually appealing, with DIVs, and seamless across all regions.