My Father purchased KBS. We got 1 quart of sealer and 1 quart of topcoat. It's super strong stuff, and leaves a great finish. It won't take much to coat a gas tank. We've managed to paint (this is from memory):
Rear axle housing
Rear leaf springs
Rear shackles for springs
Rear drum brake backs
Rear axle limiting straps
Rear axle shock mounts
Driveshaft
Front lower control arms
Front upper control arms (mount and ball joint)
Front brake calipur mounts
Front brake dust shields
Front spindle carriers
Front coil spring bottom plates
Front shock mounting gear
Steering Box and Column
Steering drag links
And we still have enough to do the gas tank once I blast it.
Follow the directions to the tee, or else the paint can will never open again. Wear latex or vinyl gloves. Use acetone to remove any paint from yourself immediatly after painting and you can avoid the week long wait as it slowly erodes.
I think the finish is excellent, and wouldn't hesitate to use it on another project.