If you're up for a different approach that weighs more and costs less, Berlebach has a nice wooden tripod (their part number 3032C available at B&H here
or in a plain finish under 3032 elsewhere) which has something of a ballhead built into it. It won't tip all the way sideways as a standard ballhead will but it has about 30 degrees of travel for getting level without adjusting the legs.
I don't know if you've seen it yet in all the links but the standard for attaching a ballhead to a tripod is a 3/8" (-16 UNC) screw thread, with the male part on the tripod. Some use a 1/4" (-20 UNC) thread, adapters are available to go up from the 1/4" thread to 3/8".
The Berlebach is a little bit different in that the screw thread is on the part you can move around; you can get a clamp by itself (rather than with a ballhead) and use it directly. A clamp like this
is a good start.
This might have been covered too but the ARCA-Swiss type clamps and plates are more or less industry standard, and they allow you some wiggle room to put the center of gravity of your camera over the tripod. The Manfrotto plates work just fine but they're proprietary and they don't give you that bit of flexibility either. Manfrotto has embraced the ARCA-Swiss pattern very recently though.
I can get some photos if you like.