Will these kits work for a zapper?

Yes. I know this kit, and I've recommended it before. It is way easier than the instructions in the Clarke book.

With the equations in the text, you can shift any of the individual output frequencies to the more "traditional" Zapper freqs (30KHz, 2.5KHz, etc.), or you can calc a new value for R2 to shift the whole group.

You might consider swapping the LM555 for the CMOS LMC555 for longer battery life. It is a drop-in replacement, and the output frequencies shouldn't shift. It has a slightly weaker output stage in the pull-up direction (square wave leading edge), but it also makes a slightly higher output voltage.

ak