The lavadrive is NOT the way to go. Unless you're already a master solderer, there is no way that a beginner could solder to the tiny smd resistors on the lavadrive.
Besides, if you have a good spacial imagination and the right parts you could make the range selecting mechanism for the RKCSTR driver very small, but like you said, you would need a host that you can drill a hole in the side for the switch.