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My recommendation would be to place all refinements into a single parameter. You mentioned a 40GB, External hard drive with a black case. How about "40gb-external-black". There is also the possibility of simply using a model number which represents the many choices available. The question becomes, what is the purpose of adding this information to the URL? Do you want users to be able to read the URL? Or is the need strictly on your end?

There are website crawlers you can employ to scan the site and hunt for specific parameters such as: http://home.snafu.de/tilman/xenulink.html

Matt may have mentioned that more is possible, but he also mentioned that he stil recommends you keep the link count at 100 or less ( http://www.mattcutts.com/blog/how-many-links-per-page/ .) In terms of LinkJuice and PR flow, having that many links on a page is definitely not recommended in any cirumstance. Simply put, the value of Juice that is passed through your links is divided by the number of links on your page (no-follow or not). So if you have 50 link juice points and 150 links, each link will get 0.333 points. (I am just using arbitrary number and the term points to make my point.)

In addition to Daniel's response, I'll offer that having the same description on every pagination version page is not helpful, though if there are enough unique products on each page, and each has a caption and or price, and you optimize each product thumbnail alt attribute, it's not necessarily a duplicate content thing as much an annoyance factor for some users. Ideally it's best to have a unique description on every page, or only have the full text description on the default category page.  Be sure however to append every page Title, URL and h1 with "Page X" as an additional way to communicate both the uniqueness of each page and for users to know where in the pagination sequence they are.

There are many things one can do to help Google recognize your business as a store. First, if your business has a centralized location, be sure to create an optimized listing for your company at Google Places for Business. As well, be sure to use selling related terms when optimizing your pages for keywords, e.g. instead of simply listing “hard drives”, use “hard drive retailer” or “hard drives for sale” along with your company name. Ensure your URL and landing page reflect your business wares as well by having a short, clear URL and using reflective keywords within the first 100 words of text on your site. It will always be a struggle to compete in Google against major corporate retailers, but by following these steps, you should begin to see a change in your results.

Thumbs up and helpful answers always appreciated