Create an approval rule for Catalog Approvables. You could for instance base it on the supplier, then requiring your group to approve.
With regards to hiding it, are you talking about hiding the catalog from end-users? Then create a Catalog View, and yes it can be maintained by customcatalog.csv and running the Import Catalog View data load. Or you can just add the constraints in Catalog Manager. If you have On-Premise you can create custom catalog filters using a java implementation, but based upon you're description, you should be able to achieve this with a Catalog View.