We use Wordpress for our main website and have been challenged with creating a proper landing page for our products. We found a great company that created a "theme" allowing you to do this. The product is Optimizepress, www.optimizepress.com. The following is a example of what we were able to create: http://mtaproducts.markettimingacademy.com/?page_id=6. The theme was very easy to use and simple to make changes. Hope it helps!
Depending on which theme you are using you might be able to prevent the sidebars showing up on "Pages". If you don't want to pay for FlexSqueeze, there is also the free Flexibility 2 theme (from the same author) which should be able to easily create landing pages without sidebars.