We've been talking about using an Arduino with peristaltic pump and interrupt sensor, or a fuel injector and pump in the "Mount and Reservoir Discussion" thread. (and there's some other relevant info in the "With two way digital communication what are your modding plans" thread as well.

The digital circuit has enough I/O pins that it could have a pin to signal z level raise directly (when they add that feature in software), and also has a pin for detecting the drips.

Since the Peachy passively detects the drips, you could basically program the arduino to step down at whatever rate you want, and signal drip with each step *(or down-up step sequence). When they get around to adding controlled z level to the peachy software, you could take that as input on a digital pin.

Rylan posted some sample source for simulating drips with an arduino as well. Peachy is designed to be easily modifiable.