I strongly recommend that you read the articles on the home page of this website. The articles are all listed in the left column of the home page. Pay particular attention to the gear lists. By making myself an Excel spreadsheet and comparing it to the "27 lb., 7-day gear list," I was able to cut my pack weight in half with no sacrifice in comfort or safety. I still use my spreadsheet a lot. In addition to consulting it when I contemplate a new gear purchase (if it isn't lighter than what I have, I won't get it), it is my checklist every time I take a trip.

Another series of articles, by Mark Verber, can be found here.. What's good about these articles is that he gives low budget options for almost everything. He also tries to keep up-to-date with the constant changes in gear models. Some of his links require a paid subscription to Backpacking Light, but I just ignored those. Avoid the extreme ultralight stuff (you don't have the experience to go there), but try to aim for the middle ground, such as what you'll find on the home page of this site. You will need a pack that will let you carry 30-35 lbs., because of your need to carry lots of extra water.

The main difference between heat in the Arizona desert and heat in Florida is the humidity. The low humidity and heat of the desert will suck the moisture out of you--you need lots more water than you think you will! Compared to anywhere in the East, you'll think you're not sweating much, when actually you're sweating far more but it evaporates immediately. The dry air also parches your mucous membranes. In fact, you'll feel as though every part of you is being dehydrated. You thus need to get your base pack weight (everything except food, water and fuel) way down so you have room for a lot of extra water--a gallon per person. At least that's what I'd plan if I were going to do this trip. I wouldn't venture off the rim in mid-winter, much less at the hottest time of the year, with only 1.5 liters! That's what I carry here in the Pacific Northwest where temps are generally mild and there is water all over the place. Please read and heed all the numerous warnings on the Grand Canyon National Park web site. We want to see you back here with a great trip report, not read about you in the newspaper!
May your trails be crooked, winding, lonesome, dangerous, leading to the most amazing view--E. Abbey