Thanks for the tag @PamCotton 
Hi @AGill9 nice to meet you.
Do you think a partner relationship management (PRM) system is what you need? Like, do you need the people you’re working with to be able to work within your system in some way? Or will the account managers be your employees with HubSpot access?
Another thought is using HubSpot custom objects, which you could associate to Companies, Contacts, and even Deals for an added layer of connection. The custom object could be Project, which you’d then associate to the partners and their companies, and the deal your team is working on. This Project could also have its own pipeline stages.
We do something similar with an object we call Services. This would require Enterprise tier and a little extra help possibly, but I think it might work for your use case.
Happy to chat more if you’d like.