You want to order when the seller is Amato Industries. I just checked the links and today they must be sold out because they are not listed as the seller for the K-2006 or the 2006C either. Wait a day and try again. They seem to restock very quickly -- at least that has been the case all summer. Try the links again tomorrow. Some of the other sellers are sending the K-2005 which you do NOT want.

The smaller kit will do fine for the season unless you have very high CYA and a green pool and are having to shock very high as a result. That isn't the case for you since you have a fresh fill. But, if you go ahead and get the 2006C, it is actually a better deal and if stored in a cool place, it will be fine for next year as well. I have kept kits for several years and the reagents have been just fine.