We want to connect several independent accounts we have with Zendesk for different support levels and products to specific support users inside our SF org so that each one gets/sync data from their respective account at Zendesk. How can we do this? and can we do this also with other apps like hootsuite for our marketing teams for example?
what you are requesting is help in integrating Salesforce and other applications (to put it in industry terms). There are several ways of solving this problem. You can do a sync across these applications either in real-time or in bulk (scheduled jobs that execute periodically, etc.). Real-time synchronization will constantly keep the information current across all systems. I would recommend that you leverage a platform which will deliver the flexibility to do both styles of integration. Who knows when your use case will evolve or newer requirements will expect bulk integrations.
It will be tempting to hand-code such a solution, but over the long run, you will be best served with an integration platform that allows you to drag, drop and connect these applications. Intelligent, pre-built connectors will improve solution time to market as well as they will abstract out a lot application complexity out for you and keep the integration simple. The connectors will also help you interact with the applications at public API levels.
As opposed to one-to-one integrations, a hub and spoke architecture will allow you to add and retire integration endpoints without bringing down the whole system.
I don't mean to make this a product pitch, and hence I've kept the information generic. SnapLogic should definitely be considered to solve this problem. Please reach out to me, if you think I can be of any assistance.