i'm searching for a lens to make fast panorama & QTVR, thus needed a wider lens with wider FOV, and of course with a good image quality...

my current system is Canon 400D (Rebel XTi) + EF 17-40mm f/4 L

my options of are:
Canon EF-S 10-22mm - rectilinier lens
Tokina 10-17mm - fisheye lens
Sunex 5,6mm - circular lens

I can only obtain 1 amongst those 3 lenses.

Can anyone share some hands on experience on any of those lenses mentioned above? really appreciate it....

thanks a lot..