Tilt option is available in some size for an extra charge
Tuuci recommends adding additonal weight to bases when adding a tilt feature-  extra 200lbs 
 
Frame/Top (Non-Tilt)
Titanium/Natural #: 79468
Titanium/Dolphin #: 80433
 
Frame/Top (Tilt)
Titanium/Natural #: 63706
 
Bases
400 lbs #: 48385
600 lbs #: 44870
800 lbs #:  64590