For AP transactions can we make a way for only Vendor Companies to populate in the drop down of transactions being entered

I have a few clients who have Company's in SCM that are both Vendor's and Customers and in the drop down the same name appears for both so they are sometimes populating the Customer company into the AP transactions that they are adding instead of Vendor. They don't want to have to change the Company name to include a signifier because then the name will not match the company name. But when you add companies to the Project Directory you cannot filter by Classification. Can we have a system setting that only allows Vendors to be in the AP features drop down when adding POs, Sub Invoices, ECT.? Or can we make the Company list when adding to the project directory filterable by classification?