I see Lightning inputField for Lookup does not support any custom object. Like if Case is haveing a lookup to Project and refer that field inside "lightning:recordForm" It does not search the Projects automatically and the input Field does not support the onchange function as well. Any thoughts?

I work with a wonderful Nonprofit that uses ADP for Payroll and Time Management, and SalesForce for client management and reporting.
They would like to use SalesForce for HR tracking (Certification and Licenses, Training required and taken - that sort of thing).  
They need the HR information (Employee info - name, hire date, department, etc.) from ADP to integrate with SalesForce to reduce double entry and maintenance.

Does anyone know of a [free or low cost is best] app or integration that can be used for this connection?  
Is anyone out there doing this sort of thing?

Thanks!
Sara