Integrating other Zoho products with CRM

Integrating other Zoho products with CRM

We are currently using Zoho CRM on a trial basis. My questions are as follows:

Can different users in a company subscribe to different editions? In other words, d o all users have to upgrade to CRM Plus in order for a few users to access Projects Management?  Do all users have to use the Enterprise edition in order for a few users to access Zoho Support?

Thank you,
Marie