What type of plan do I need to use the HubSpot <> Collect integration?
On Collect side, you need a pro plan and above to have access to the HubSpot integration.
On HubSpot side, you will need HubSpot Sales Hub on your account. If you want to use Workflows you will need Sales Hub Professional.
Please note that you will need a user account in Collect for each user in HubSpot that need to have access to the integration.