Correct configuration for CMOS inverter
For a drive current of 100 µA, you don't need multiple inverters. The Arduino can drive all the noninverted outputs directly, and a single inverter can drive all the inverted outputs.

If the signal is being generated by software and you've got an extra digital output on the Arduino, you could perform the inversion in software as well and drive the inverted outputs from a separate pin. Again, a couple hundred µA from one pin is not a big deal.