Vendor Managed Contracts

We are in 12.1.3, and planning to implement Service Contracts.  We are do an fit GAP analysis.

We have below question.

We re-sell some of the services, but the actual service will be provided by the vendors.

For the vendors we need to create PO's and receive that PO monthly so that we can pay them.  We bill our customers monthly same way.

Is there any way in Service Contract module to link an Vendor PO to the service contract.  When the PO is received monthly it will bill customer automatically.

Right now we are doing as dropship in Order Management, but we are missing other features like Contract start dates, end dates, tracking service tickets and service serials and contract renewals.