Take a look at the Laos laser controller it uses a Arduino board and is completely open architecture with a lot of hardware and software support. I am currently assembling the electronics to control a 50 W no-name Chinese CO2 laser. With a few parts on hand I think I will have it operating shortly at the cost of approximately $150. The free software used is Inkscape and VisiCut.
I think this is a little known secret and I'm just trying to get the word out.
Here are two links to get you started:
Webshop | TuxIC
HPC LS3020 Laser Cutter - Fablab NB + JL - JeeLabs . net