Well, I wouldn't do sorting by Manufacturer. Many people don't know who makes what products. But since you're working on that, I guess that really isn't an issue.
Also, sort of off topic...
Is it really worth it putting all of this work into this site when it's a front for reptilesupply.com? Have you received affiliate funds succesfully through sales via your website? I signed up as an affiliate and after 3 months of not receiving a dime (when I know people were clicking what I had on my site and purchasing), I removed the link and am setting up a webstore for products I actually have in my posession & sell.