Thanks for all the advice, everyone. After mulling it around, I've now got my eye on this one, from Austin Homebrew Supply:
http://www.austinhomebrew.com/product_info.php?cPath=178_33_463&products_id=10460A couple of reasons:
It's 10 gallons (I think everyone agrees that's a good idea)
It's 1.2 mm thick (heaviest duty SS I've seen)
It's the cheapest pot with these specs (w/aluminum core bottom) when you consider shipping
I'm going to go with just the bare pot for now. I figure I can add the spigot and thermometer later if I want them. (cost IS a consideration for now)
One note about the NB pot mentioned: It's listed as 10 gallons, but the measurements appear to add up to ~12.75 gallons.
(Pi * radius squared) * height / 231 = gallons
(3.14 * 8.5
2) * 13 / 231 = 12.7672