Unfortunately, such a list might be misconstrued as an endorsement of the particular businesses, by the website. A poster/member has an unfortunate poor experience and the whole forum can suffer, plus loosing an active member. Getting individual parts into the mix can be trouble, too, by observation.
Plus, as time progresses, unless the list is kept current and updated regularly, it can become "stale".
On the other hand, just a listing with a link to the business's webpage might be a good deal to have, as many other forums/blogs do. Individual businesses could request they be listed, if desired. Such a list might be "a sticky" at the top of one of the forum listings.
Making use of the "Search" function might also get you the information you are seeking as to where to get things, too. Sometimes, "the search" is more fun and educational than any spreadsheet might be.
Just some thoughts,
CBODY67