You should try the PickyStory app, which allows you to cross-sell and upsell product bundles across your store. It is added automatically to your store and pretty easy to customize (also code free). You can create manual and automated bundles and place them on any page in your store. Also, you have an option to add a 'Complete the set' button right next to the Add to Cart button to offer bundles when shoppers are adding products to cart.
Hope this helps!