Need some advice...

[What's_nitro?]

I actually have the shell of a nerf gun that I think it could be built into, sans the gigantic main capacitor.

I'll probably make the housing from polycarbonate since I have a good stock of it already. The circuit in the picture will fit onto a small (2"x3") PCB, which is nice because that will keep everything neat.

A small tip on the schematic- The pink lines represent the barrel of the gun. The zener diodes keep the system operating at exactly 12V to guarantee consistent operation.