Octane is the most important IMO, the other little bits of mods aren't as important to get you to where you'd like to be.
The advantage is if you have 93 or higher available around, you will have different maps to choose from regardless JB4 or Cobb.

-Payam

 

Once filled the meth tank lasts a while. Most use the snow meth kits. Its a progressive kit, starts at 10 goes full spray at 20. In regular spirited driving you rarely use any. It helps a lot with IATs especially in the summer. I have the 2.5 gallon tank, it takes about 10-12 full 1/4 mile or 45-140 pulls to make it hit the low sensor. If its low the gauge flashes, so theres not much to worry about it. I'd be more worried about trapping high 130s on pure 93 than anything else.