Menu Help

I am having trouble with the menus in hikashop. I am doing a candy website with over 1000 products so when you go to "sweets" in the main navigation i want a permanent side menu with all the different categories of candy. Joomla seeems to only let me load it in the "components" section which would be ok since I can just make a second template and switch the "components" section and "module 1" locations and link it to that page only. But then when you click on an item the menu disappears and the item loads in the same "Components" slot. I would like the menu to stay in the "module1" slot and display the various products in the "components" slot. Here is an image of what I mean: