There is no "best"; opinions abound. There is a best for me or you and only research and experimentation will give you "your" answer.
For me, the best combination so far, is the Kirk BH-1 ball head with the Velbon Carmagne 630 carbon fibre legs. Depending on the weight of your setup the Kirk BH-3 is about a pound lighter and is highly regarded. It (BH-3) was not out when I bought mine or I might well have gone that way.