First, I need to specify I'm very noob, so maybe in my situation a vague awnser is better than something very specific, I don't know.

I want to make an airbow (airgun that shoots arrows) like the one Joerg Sprave made on his YouTube channel. Except, he powered it with a 12 dc battery, whitch is very straight-forward, but also quite expensive and heavy, compared to AA or maybe higher batteries, boosted with a capacitor. The thing is I know nothing of what to expect about the output of the capacitor. I know it can be quite high, because once I made fun of shocking myself with one made for a flash, with friends, and it gave quite a jolt. Anyway.

I want to have a switch button, once pressed it would give power to the valve just long enough to deliver the compressed air and shoot the arrow, so it doesnt need long, once the arrow it shot, any excess air is futile. If it's simple to install, I would like a LED to signal when the valve/gun is ready to fire, but it's optional. 

I can go a bit with trial and error, but I wouldn't fry my valve in the process since it's the most expensive part of the project yet. I dont mind a schematic for the circuit if you can provide, but (ok I know I sound very helpless) if there was at least some clear note (e.g.: your valve, power source:aa battery), it would help me a lot to understand the big picture. I'm sure I can, but the last time I worked with electronics was more than 20 years ago, and I'm 37.

I hope my question is not too boring or too easy or too vague, thanks for any help.