Just saw this resource mentioned for architects. https://materialdistrict.com/ Hopefully this comes in handy for you!
Category: Specifications
Resources related to architectural specifications to help you get started and make sure that your project is thoroughly and correctly specified when it goes out to bid.
Sweets Catalog
https://sweets.construction.com/BrowseByDivision
Arcat
https://www.arcat.com/
4Specs
Great resource for finding manufacturers and distributors for most construction products. www.4specs.com