Category and Attribute Setup

Thanks in advance for any help given:) I am developing a new site and am new to zen cart. The main product to be sold is fabric. I want to be able to shop by: Fabric Manufacturer Fabric Designer, Fabric Collection and Print Name.
This is the setup I'm going for:
Fabric Manufacturer Page(manufacturer name links in list view on page with alphabet search across top of page)
Fabric Designer (list view on a page)
Fabric Collection (grid view 4 across -complete collections)
-separate color palettes
example: Fruit in White
-----------------
Fruit in Blue

1. Would it be better to make each category a subcategory of Fabric Manufacturer or to just link each of the categories?
2. More importantly, I have setup my attributes and options to sell in any 1/8 yard increment or 1,2,3 yards etc. I need to know how to keep track of the available stock. Say I start with 15 yards in stock and a customer buys 1 3/8 yards I need it to say there is still 13 5/8 available quantity.

1. I'm not sure exactly what you want to do, but the Manufacturers function in Zencart allows you to assign a manufacturer to each product. There's a Manufacturers sidebox which lists manufacturers and displays all the products from that manufacturer when clicked. You could also use the EZ page function to link to manufacturers and enable those in the header. I'm not sure where you wanted the manufacturers links to appear.

2. http://www.zen-cart.com/index.php?main_page=product_contrib_info&products_id=310

I haven't used it, and I don't know if it can calculate fractions.