@Ashley Ayan
The standard Content Recommendation Engine for RTP doesn't have a lot of customization available in it, which is why we came out with the new Rich Media CRE, which gives you a lot more control over customizations.
Here's the Docs article about it: Enabling the Rich Media Recommendation Engine - Marketo Docs - Product Docs
Don't worry about the mention of the Beta at the beginning of the article--I just talked to the Support Engineer working your case and got that enabled on your account.
Here's the Developer's page that shows a lot of the code needed to get it up and running: RTP Rich Media Recommendations API » Marketo Developers
Hope this helps!
Mike