I am trying to accomplish the same thing, what I am currently doing is adding a simple option titled "Brand" with the only option being the products brand, then under the results page edit the query to select only the products with the option of that brand. I have not had any luck with this however, mainly because the database tables are as you say "very custom and difficult to understand" I am wondering if anyone has the syntax for the query to select all the needed data, or if anyone has succeeded in accomplishing this a different way any information would be helpful.
Thanks
