I bought both the arduino shield and the non-arduino driver board. Both work great.
I couldn't find the schematics for the arduino shield in PDF format :-(
Since I am going to use IN-9 tubes in a automotive environment, the driver needs to be pretty robust (vibrations). Unfortunately the arduino board has no mounting holes and the non-arduino driver board does not allow to fixate the big transistor to the pcb.
If rcs27 is going to design another driver board with four or more channels, I'm the first one who's going to buy this.
Great products. Super fast shippment, top packaging.