I have used a couple digital ballast with my Growtronix system. Lumatek was horrible. I got a Quantum that was much better. When I first got it the first 4 or 5 minutes after firing up the ballast would mess with the system then be rock solid. After a year or 2 of use it seemed to start...
Same as with Asbestos4u I planned on buying from them. I e-mailed back and forth and it seemed they will make a box to do what you want. In the end I came in over budget so just ended making my own.