Based on all you have written and said you are best suited to a new Sigma f/3.5 8mm Fisheye lens for your 7D.
This will require 4 rotational shot at 90 degree click stops (Yaw). I.E: A shot at 0, 90, 180, 270 degrees. If you tilt up +5 to +7.5 degrees on the panohead whilst shooting the rotational shots this will close the small hole at the Zenith. Leaving you will the tripod to cap (or patch).
Sell off the old Nikon Coolpix and FC-E8 and use that money to upgrade your 7D kit. I.E: Sigma 8mm Fisheye and a decent Panohead.
The quality will be a HUGE difference over the FC-E8 and yes even more will be gained with knowing how to get the most from the combination with experience and tips and tricks etc.
This little tour of mine is made with the Canon 7D and Sigma 8mm Fisheye www.omnipix.com.au/panoramas/2010/tucker_van
I have multiple lightly used DSLR panoheads for sale if you need to save some cash or I'm happy to point you in the right direction for purchasing new.