convert existing html page to our new format xhtml design

Hi we have just had our website redesigned to a xhtml css tabless structure however alot of our business listings pages are still in our old html format and need to be changed to the new xhtml css format and then use the new layouts as templates so i can then duplicate these for new advertisers I have around 25 pages that need moving across to the new format, the majority of which are a simple design, I would be happy changing these designs if neccesary and perhaps having 5 different layouts that customers can choose for future use? Thanks very much