Re: SLR LENS for Antartica 2009!
And your question about Gitzo....ABSOLUTELY! To quote one of my favorite photographers, Joe McNally....."No matter how many megapixels you've got inside that fancy machine you hold in your hands, they aren't worth beans if you don't hold your camera steady." Look at the photos from any photography trip and pay close attention to the photos of the photographers themselves - not a single one is without a killer tripod. Most are using Gitzo because the carbon fiber models are light-weight, sturdy, and can get extremely low to the ground. Light-weight for ease of carrying. Sturdy to hold the heaviest of gear and withstand the wind. Low to the ground because you'll want to be eye-level with the animals to convey their world.
You'll also need a good ballhead. Acra-Swiss, Realy Right Stuff, and Markins build the most popular professional/pro-sumer models. Markins and Acra-Swiss recently redesigned thier top models to be smaller and lighter. RRS will hopefully have some new designs soon too.
B&H is a good place to buy Gitzo and Acra-Swiss from (bhphotovideo.com), but you have to buy Markins from Markins USA. For your gear, you don't need the top of the line....that stuff is for super telephoto glass.