Re: A few practical questions
1. The weight limits are not too bad. Consider that you will be wearing much of your cold weather gear on the flight from Christchurch to McMurdo, and that will not be included in the total. Laptop and camera(s) are a must. I personally recommend the Olympus Stylus. My model 1000 did very well this past year.
You can also mail packages to yourself via the U.S. Postal Service, or have friends and family mail them to you. U.S. domestic rates apply, assuming they are sent from the United States. Due to a recent change, packages mailed to Christchurch on your behalf must be treated as being mailed to New Zealand (which, after all, they are).
2. Internet at McMurdo is 24 hours a day. There are some restrictions on usage of high bandwidth, but they won't normally affect normal web browsing. There are some other restrictions as well, which I'm not too familiar with as I spent most of my time at the South Pole Station. In any case, you will have plenty of opportunities to access the net. South Pole has the same bandwidth restrictions, and only has internet access 11 hours per day (when the equipment is working).