needs to be compacter less negative space, atm it looks empty even if it isn't, you need to convice the users that your shop is full of stuff. Header needs some serious work, if you are not good with photoshop let somebody else do it if i have time today I do you some.
Navigation and searching for products should be an easy task because all the items are properly arranged and categorized. There's even a product search bar included which makes thing easier. Overall, nice looking and user-friendly site.