... and short answer is RRS. Long answer is:
...and I guess the main questions would be what do you want to
shoot and what do you want the output to be? Other questions:
Spherical or Cylindrical?
Is weight an issue?
Are you the kind of person who wants precision from one of these
machines?
How will you be stitching these images?
What tripod do you intend to use?
I shoot mostly real estate and wilderness cylindrical panos that
are rendered into QTVR movies. I have also successfully shot panos
with a monopod, hot-shoe bubble level, and a compass. It comes down
to tradeoffs. Weight, precision, and ease of use.
My current favorite rig is (top to bottom) Nikon D100 in BL-D100
"L" bracket (Kirk) fitted into a Kirk LRP-1 fitted into the RRS
PCL-1 mounted to a Manfrotto 3416 leveling head that's mounted on
my Bogen 3221WN tripod (similar to the whole RRS "Horizontal"
setup). This is far more solid than the Kaidan and breaks down
nicely for packing/travel. I can also very easily use the top two
pieces with a monopod if I wish to.
The tradeoff is not having the convenient click stops.
Check Manfrotto as well:
http://www.manfrotto.com/product/itemlist.php3?manufid=1 §ionid=11
Good luck! Panos are a lot of fun (and hard work).
Kent