I simply don't believe that they, or any other retailers, have a brand new SB-600 in stock. If I thought that was true, I'd be ordering it right now instead of typing this reply. I would expect you to get a call from them after you order so they can offer you some substitute.
Recommend you always check ResellerRatings.com before buying from an unkown online retailer. There are a number of bait-and-switch folks out there who can be very frustrating to work with.
If you absolutely cannot afford a SB-700, you may want to consider Nissin or some other alternative - with an understanding that you have to be very careful to make sure they are completely compatible with Nikon's CLS/wireless capabilities. I used to recommend Sigma, but their latest products are not compatible with the D7000s wireless system according to their compatibility table.