Any height, weight limits, budget, travelling requirements?
Carbon fibre ones are lighter and stiffer, but a premium over the other materials such as aluminium for instance. Get something of a height comfortable for ur eyes ( personally I do not even use the centrepost but if u r really tall then it is another story )
Get one that supports ur heaviest setup. Dun not get a cheap setup and lament when it doesn support something else down the road. Spend bucks to save bucks, going cheap and u might spend more, & u would loathe to get another setup. It last u ur many other nikon bodies.
Whats budget ? Gitzo is a pricey tripod maker that is well recieved. Good ballheads includes Arca Swiss, RRS, Acratech, Kirk, Markins, etc. They provide good and smooth tension control, more durable, great load to weight ratio
There are many other factors in deciding tripods / ballheads, u might get more resources online
Visit the various shops to try the tripods / feel the ballheads.
Ryan