Quick question about Borderlands' DLC

Steam is having a sale I want to take advantage of, 66% off of Borderlands and it's expansion packs. I only want one of the packs, "The Secret Armory of General Knoxx". My question is, do you need the two previous add-on packs before you can access this one? Thanks in advance for any help. :)

EDIT: sorry for my bad wording, I was in a hurry, I meant I wanted the one add-on pack with the core game, I just don't want the previous 2 add-on packs.

Oh, then yeah, they are separate purchases and do not require the other expansions to work. But Zombie Island is also fun and very humorous.SerOlmy

Like others said considering how cheap it is should get island of Zed also. Moxxi only if you have friends to team with.

Well if you like Borderlands keep an eye out for Rage coming in 2011. Pretty much another borderlands with better graphics.