g'day Shea,
Drop tank Neg. -no foam to reduce fuel weight shift
-possible damage when lowering car closer to the earth
-fuel heating due to being closer to the exhaust
-Need to make a return line if going injected
Pos. +If its already there, use it
+good lower center of gravity
+gives space in the boot
Fuel cell Neg. -have to make it a remote fill due to the new laws
-takes up boot space
-tends to make the car smell of fuel(even with no leaks)
Pos. +Foam filled
+Reduced chance of cell rupture in accident
+smaller dimension for reduced weight
+extra return points for different fuel setups
Hope i haven't made the decision harder