would this be enough?

Cable size goes down in number as it gets larger. IIRC each size is 25% more cable diameter. 6 gage is 25% smaller than 4, etc. they go down to 2ga, then 0, then they go 0/1, 0/2, 0/3, etc. Welders cable uses fine diameter copper wire in the cabe, and it is MUCH more resistant to vibration then std multi-strand cable. The resistance is much lower in welding cable vs battery cable for the same diameter and length. The switch, done neatly, will take a couple feet of cable. I run cables down the left side of the car to keep them away from the fuel line. So my route takes a longer cable. Add the negative, and it's more than double what that kit has. But, the reason stereos need special cables and big wiring is because it affects the sound. Same deal with the performance of the electrical system. I also add an underhood buss for the high amp accessories. It might be overkill. But the cars don't have the typical wiring BS even years after, and that's being abused...lol. If this is a straight out drag car, the kit should be fine. A bracket car I would wire MUCH better tho. Just my opinions. I'm sure others have it done differently with success.