Hi James,
Definitely loading information into Eloqua CDOs for opps, product and other relationships you might need to segment your contact records is the best approach in this scenario. It is important to include some considerations when it comes to using that data in emails or field merges in general. We have done similar implementations for multiple customers and can help you though this process as well. So feel free to reach out if you'd like to discuss further.
Best,
Sam Burgoon
Marketing Automation Specialist
Office: 408-622-0084
Skype: sburgoon4tm