Depending on your business model and contract, you might not want your clients to see the source and vendor for the product selections provided.
1. If an existing client, open their profile on the project and click "Edit Permissions"
If they are a new client, the same permission controls are shown when you send their invitation.
2. Click on Collaboration settings…
3. Toggle "View product sources"
This will control if they can see where the product is coming from, and any other information you included about the vendor, SKU, website, etc.