In the store I'm setting up, there's an Age attribute for each product, and I'd like people to be able to use that to filter product lists, similar to how you can now with Manufacturers. (I'd also like to appear in the same list as Manufacturer on the Product page, rather than down with the selectable options like color or bulk size desired.) There may be other attributes added in the future too.

I'm pretty good with PHP and MySQL, though I haven't done any hacks to Zen-Cart yet; this would be my first.

Any advice from those expert Zen-Cart coders out there? Should I use the existing Attribute system and try to hack around it to do what I want? Should I add a custom MySQL column to products and create a custom input field for it in the Product editor? Anything I should read up on first?

And has anyone done anything similar?

Thanks!

PS: It seems like this should be abstracted through some sort of Core Attributes sytem for each product, as opposed to the current selectable attributes system.