Implement buy sell relationship for indirect procurement across multiple BU's and ledgers

Summary:

We would like to implement buy sell relationship for indirect procurement where a centralized BU will procure items ( expense) and resell to other BU's across ledgers. In this regards, i understand that we can leverage Supply chain finance orchestration functionaliy. However i would like to clarify the following questions:

Content (required):

Can we implement the functionality without having to implement inventory module as the requirement is related to indirect procurement?

If we can implement the solution without inventory, please elaborate on solution options to implement.

Are there any other modules that are required to be implemented to establish this function such as for transfer pricing, costing, AR etc. If yes, appreciate if you could explain the need and any alternative solution path if applicable