Sales plan in PP for materials which are purchased for purpose of reselling

Dear SAP gurus,

At our company we use HR, MM, SD, FICO, PP modules, SAP ERP ECC 6.0. I am trying to find solution in SAP which which enables most basic Sales planning where I am able to make entries for target sales quantity, target sales total amount, etc. on monthly basis, on material and plant level. After some research I found that for this purpose it is best to use:

#option 1 - APO (as part of SCM),

#option 2 - APO Add-in for SAP ERP (ECC) or

#option 3 - stick to core functionalities of SAP ERP (ECC).

Since there is very little chance my company will decide for options 1 or 2, our goal is to make best of option 3! Closest I have found is this link blog https://blogs.sap.com/2015/08/13/sales-operations-planning/ under section STANDARD SOP for Material.

It seems that Sales plan is under PP module. Since we have little materials that we produce, my question is can we still make sales plan in this module, for materials which we didn't produced, instead we have purchased the for purpose of sale to other parties (reselling)?

BR.
Sam