i looked for numerous methods for adding additional information and generally came up with a mod that did half of what i wanted, but never everything that i wanted.
i therefore tried to do it myself, with some success. i managed to duplicate the manufacturers field (for reasons different to yours) without too much pain, although it did take me around 4hrs (depends on what you call pain). this effectively gave me a second dropdown in each product definition, along with it's own management interface (i used it for categorisation independent of anything else) for creating/removing/editing entries, as well as mimicing the "URL" and image fields that you see with manufacturer. mine is not complete yet, predominantly because i'm still trying to add it this new field as a second filter to the user interface but i would imagine it would work perfectly for you as you don't want the user to see it, and it would take half the time as you are only interested in admin files.
- i duplicated the manufacturers, and manufacturers_info tables in phpMyAdmin, renaming all columns appropriately to the new category (without the data of course)
- i added a new "xxxxxxx_id" column to the products table (replacing xxxxxxx with the entity you are interested in)
- i used the "look-up in all files" facility (developers toolkit in the admin interface) to search all instances of the word "manufacturer". yes, i got a lot of results, but depending on your knowledge of zen-cart, and the product types you are using you may get away with only modifying 10-15 files. i printed this out so i could cross items off as i went.
- for each instance of the word manufacturer, i effectively duplicated the code for my purposes. this means for all global variables, all page variables, all PHP code and all sql. really not as daunting as it sounds, however...
- the last step was to create the files necessary to display the appropriate management tools in admin. as they all appeared in my previous search, this became quite evident simply by looking at the filename i was editing and the code calling/including the file
obviously, i haven't tested advanced searches and reports through the admin interface as this was not my desire, but i think you would probably have success within a days work if you put your mind to it.
last comment would be to ensure you back everything up, and use overrides! obviously, the layout of manufacturers requires modifications to the products table, so upgrades might get tricky down the track and it would be advisable to dump the database to file before upgrading t oavoid problems.
