If you can stretch your budget look a geared heads too. eg Manfrotto 400/405 and 410.
I've got the 400 Manfrotto, its a monster handles everything I've thrown at it, its awesome, you can make very small movements in all 3 axis's. I've used it with a D2x fitted with a 70-200 2.8 zoom no problems.
In my experience ball Heads are OK but as soon as you put a bit of weight on them they can be troublesome, they tend to slowly sink towards the centre of gravity unless you really tighten them, then when you *** to make a small adjustment the shear weight makes it hard to do.