Thanks, everyone for your suggestions. Regarding Krazy Bills suggestion that I just purchase more CF cards:
Some of my photo projects involve traveling in places with very limited amenities for a week, up to a month. The activities I photograph on these trips, Cedar Canoe Journeys, can use up two or more 16BG cards each day. Multiply that times seven, or thirty for a trip coming up in a couple of years, and that's a lot of CF cards. I'm thinking a MacBook with two or more portable 2TB drives to down load the cards on to. Would also be nice to look at photos during the trip. Shoot Raw NEF and jpegs. View the jpegs on the MacBook, as they will be smaller files.
What I'm not sure of is how much RAM I need for this. Probably looking at 2.2-2.6GB processor. Another consideration is the battery. Somebody mentioned removable batteries. Would allow me to have two or more batteries. I've never used portable drives but assuming they power off of the computer they are connected to.