I use a big stainless pot. It is a Belgique from Macy's. They have many different ones and are significantly less expensive than the one you linked to (and one that I have also has the pasta strainer insert, though I haven't used it when making stock....good idea!).
http://www1.macys.com/catalog/index....inless%20Steel
All Clad is definitely heavier duty and very nice but if I was going to spend that much on a pot I'd be getting a huge Le Crueset dutch oven

( and I do have one and it is awesome but I bought it second hand so it was much less expensive).
If you do decide to go with that one, make sure to check out places like TJ Maxx, who often have AC pots and pans for a big discount.
