[The Hub Client] Make Custom Products Available in the Hub Client

I have created a number of addons that my clients can use to enhance their experience. This includes things like web design, SEO, marketing, and other services.
Currently, clients can only purchase by visiting a custom built page on my main website. This would be fine except it presents a couple glaring issues. First, they have to leave the hub client to access it. Secondly, and worse, I either have to leave that page publicly accessible OR I have to lock it down and the customer needs a separate login to access it.
SO the feature I am requesting is that the custom products would be able to be ordered from the clients account inside of my Hub Client. They would have a page they could go to where they can select desired addon, add them to cart, and checkout – all without leaving the hub.