Most tripod manufacturers have a calculator on their website to help you find a tripod and head that will properly support your camera. You need to know the weight of your camera, heaviest lens, a battery, and other accesories you might mount on the camera such as a light or wireless reciever.
Here is a link to a configuration app on the Manfrotto website. You can find similar features on the sachtler website, etc.
http://www.manfrotto.us/Service/Tripod+%2B+Head+Chooser/About+the+Camera+Support+System+Configurator+-+Tripod+%2B+Head+Chooser/3670750
