If the laser modules you buy do have a driver, and not just a current limiting resistor, then you can wire them all in parallel and power them off a single 3v supply.
I think these do have a driver.
50 x 650nm Red 5mW Laser Diode Module Dot 3VDC Pointer | eBay
Not sure about these.
Color the lens on your red 5mw pointer with a blue magic marker. :san:
You need a larger budget buddy. And yes there is a very noticable difference between blue and violet.
This would be your best bet.
50mW 450nm laser pen /single mode/round dot [OL-450-50P] - $82.00 : Zen Cart!, The Art of...
This type of question comes up all the time, and the short answer is... No. You can't take a 1mW diode and turn it into a burning laser. The little diode was never made for much more than 1mW or even 5mW what ever the case may be. You'll need at least 100mW before you get into the "burning"...