Better product search in Oscommerce by assigning weighted relevance

The default sorting of product searching in OsCommerce is terrible. We made a very crude and simple hack to the mysql fetch, but we would ideally like the products to be sorted by relevance by assigning weight to it. The prioritization of returned results should be ranked in this order: 1. Number of matching keywords in the product name. 2. Number of total matching keywords in both product name and description. A relevance score method should be assigned, and an option to set the minimum relevance score to ignore/hide all results that don't meet the minimum relevance score. We would also like to have slave products always shown always in order with the master products being returned in the search results, regardless if it is searched by master or slave keywords/catalog numbers. Currently, the slave products are treated as separate products from the master products, and this confuses customers who see them appear in random orders in the search results. Note that we are using version 2.2MS. We also added Master-Slave products contrib, with a many extra hacks and additions.