Racks & Bags - A solid frame mounted rear rack & rackpack are required. Panniers can hold lots of gear. However I don't like them, since they act like sails in the wind. A normal rider will average 1.5mph faster without panniers. These miles add up for a multi-week tour. I came up with an interesting solution to carry my stuff and keep it all behind my back to minimize wind resistance.
I wanted to speed up my riding and still carry all my stuff. I bought a small camping grill. I put the grill portion over my bike rack and made a super duper rack. I found one of these on amazon for about $11.
Using the rack with bungee cords I was able to attach all my supplies ( sleeping bag, mat, mosquito net, camping stove ) behind my body. This minimized wind resistance, and I was able to bike about 1.5mph faster which is huge on a loaded tour.
The below photo is exactly what you should stay away from. The panniers slowed me down way too much.