Depends on the camera. Most tripods and heads have a weight rating. Make sure that the head and legs can both support the weight of the body and lenses combined.
I was recently looking around and settled for Manfrotto 055PROB legs and a 804RC2 head. It is solid enough for my 40D/5D and can be twisted and turned in all directions thinkable. You can choose between a video type head or ball type head, but it comes down to personal preferance rather than one being better than the other.
Manfrotto are good for middle of the range, gitzo for the top and jessops own/ velbon for lower. IMHO.