shocking idea for a game

[fried]

Hi all,
I'm brand new to the forum and looking for some help!
I'm a ba 3d design studentworking on an idea for an electric shock game.
I need to build a circuit that will be able to accumulate charge from a dynamo and only discharge when it reaches a certain (safe!) level.
my initial thoughts are to use a hard drive motor as the dynamo, and capacitors for storage.
from my research it seems that it can be safely assumed the resistance of a human body is around 1000 to 1500 ohms -ish
and a safe but shocking current would be around 5 to 10 mA dc. so about 5v then?

what kindof capacitors would I need to use?
how do I work out the required capacitance?
can anyone help with suggestions for the circuit?
hard drives use stepper motors. what kind of output am I likely to get? am I right in thinking that I could use a diode arrangement of some kind to charge the system regardless of which direction the motor is spun?

I need to keep weight to a minimum.

As you can probably tell, my electronics knowledge is limited to gcse level (probably less) and forum lurking.

any help with this project would be hugely appreciated.
thanks,
josh