Maintaining sidebar in dynamically created MarketPress category pages

Hi folks! Sorry if this has been posted elsewhere but I searched and could not find a specific solution for my issue. I have been testing out MarketPress and am looking to migrate my online store to the MarketPress platform. While I have been able to maintain my columns and sidebar with the custom posts products, my categories are all in a one column layout. From looking at the gridmarket theme I see it is possible to alter this layout but I do not see how the page can be directly edited. I've a small amount of html and css experience but I would appreciate it if someone could give me a little guidance so I don;t break any functionality. If it helps, here is the single product page that has the layout I would like for my category page tulle-shed.com/blog/store/products/beige-netting/" target="_blank">http://tulle-shed.com/blog/httptulle-shed.com/blog/store/products/beige-netting/ and here is what I have currently in my category page tulle-shed.com/blog/store/products/category/nylon-netting-spool/" target="_blank">http://tulle-shed.com/blog/httptulle-shed.com/blog/store/products/category/nylon-netting-spool/ Thanks for your time!