If you are looking to replace your controller, or are just building your machine, do yourself a favor and check out Super Gerbil. A friend of mine has developed this and is running his Kickstarter now. https://www.kickstarter.com/projects/2118335444/automate-anything-with-super-gerbil-cnc-gcode-cont?ref=discovery&term=super%20gerbil
https://www.kickstarter.com/projects/2118335444/automate-anything-with-super-gerbil-cnc-gcode-cont?ref=discovery&term=super+gerbil