I offer slightly different products from the template in my instance.

No problem! Here's how to adjust the template to fit your product offering:

Create a new category for your unique products by going to Settings > ECommerce > Categories Then duplicate the products in the template that closely match the products you want to offer. From there, you'd just need to add either a new attribute or new parts that reference existing attributes in each of those new products to help you customize the product to your specific needs. 

*Do NOT delete products, attributes, or parts completely out* You can always discontinue or hide any of these things so they aren't showing to your customers.