Lets say the tripod is rated to take a load of 6Kg, what load rating should I match this tripod with for the ball head? Should they be the same, or slightly more? 8Kg?

At first I thought the same load rating should be enough, since the max that you load would be the lower of the two parts, but after talking to Christopher from CP, he said I ought to get a ball head with a slightly higher load rating than the tripod.

Thinking of getting a Manfrotto 055CL (rated at 6Kg), with a ball head (Compact, Midi for Manfrotto, Ball head 800 for Slik). Anyone having this set-up? Inclined towards the Slik 800, so much smoother than the Manfrotto. I know, I know... Acratech beats em all, but no $$$!