New E-Commerce website maybe Business Catalyst

As a spin off of our core business, an opportunity has arisen for us to sell documents online. A bit like manuals, but we would sell policies and procedures to clients for a commercial rate. The materials need to be supplied in word so that the customer can customise them for themselves and integrate them into their own operation. We already have the domain name and hosting, but we need to have someone build the website and the e-commerce plug in. We already have the library of documents. We have an existing relationship with Business Catalyst for our principle website, and thus easy in once sense to retain the common software, however, it si 2018 and other options may exist. We figure it is a library view, tick the docs you want, add to the shopping cart and pay be secure transaction. We figure we need to offer a demo page, or half page and then they pay for the full page. Probably up to 500 documents. We need the front end, the e-commerce and the secure storage of the documents. Clearly, we know the documents, but not the website or how to manage the e-commerce. We need advise on design etc. The attached doc in PDF is a sample if what we would sell, price range is uncertain but between say $25 and $100 per doc