Seller Negotiations for Internal Users

Summary

Can we invite Internal Users only to Seller Negotiations?

Content

Hello,
Is it possible to create Seller Negotiation and invite Internal Users only instead of Suppliers?

The client would like to sell excess inventory or retired assets by offering them for bids to internal users first (can't find this option), afterwards they would like to offer to the Suppliers (this is currently possible).

We know that we can do that by creating each Internal User as a new Supplier and Supplier Contact but it is really not a good and clean solution to present to our Customer.

Thank you,