Here is the example I showed you…
http://demos.templatemela.com/woo/WCM01/WCM010013/WP1/product/nullam-mollis/

Here is another sample example….
http://demos.templatemela.com/woo/WCM02/WCM020044/WP1/product/cras-eget-augue/

In both cases, the tabs appear to the RIGHT of the sidebar directly underneath the product image and add-to-cart without a halfpage full of whitespace, or more .. depending on how far the sidebar goes down the page.

Hope this helps.