Power Supplies for DIY Scanner

Hi Guys,

I'm looking to make a diy scanner following schematics found here: https://sites.google.com/site/projec...aser-projector
Though I have a good understanding of basic electronic principles, I'm still quite new to diy electronics.
I've done some research on arduino and scanners in general but one thing I haven't found was information on powering the lasers, scanners and microcontrollers.

Could someone point me to a good source on powering electronic projects or perhaps offer me some advice?
I'm looking to buy a relatively cheap set of 20kpps galvo scanners off ebay which comes with it's own power supply. I was wondering if if I could also power both the laser, the arduino board with this or should I build another PSU?