Potential New Project-- Airsoft pistol to laser

Hello. I'm debating starting a project where I convert an airsoft pistol to a laser emitter, for melon-hunting/plinking and possibly self defense, however, I'm not sure what strength I should use. I was debating acquiring a Blu-Ray player and cannabalizing it for it's diode, but I'm not sure if this would work well or not. On top of this, I plan on using the pistol's magazine as a removeable battery compartment. Any help would be appreciated.

For reference, this is the pistol I'd be using:
http://c.shld.net/rpx/i/s/pi/mp/198...pg&d=751bc6e3f9244478b48b4a95ab3ede689d4edc16

you do realize that as cool as they are lasers are not toys so if you are going to be using it like you describe here is a link to a 5mw laser module off ebay.

Industrial Lab 3VDC 532nm Green Laser 5mW Diode Module | eBay