I'm interested in following your project too, but don't have much time myself unfortunately.
> However, some electronics work is also going to be required, and I'm
> not so good on that front. I have a couple of small incubators which
> I've used in the past, but they are not temperature or humidity
> controlled. Ideally I'd like to hack them to get them working on a
> thermostat and set up some kind of process to monitor and adjust
> internal humidity.
Ultrasonic humidifiers with condensing chambers and a timer are often used. If you want about 90% humidity, it is easier and more reliable to just fill the bottom 3 or 4 inches of the incubator with perlite. Add steralized water until damp and make sure the top seals reasonably well. Add some books on the lid if necessary. This will keep a high level of humidity for ar least a week at a time.
You can add a bottle of Hydrogen Peroxide to the water if contamination becomes an issue. Do not use Schultz brand perlite or any other that contains bits of wood or other organic matter, this will begin to rot and lead to contamination.
If you have several incubators try both methods and let us know how they compare.
www.shroomery.org has a wealth of knowledge for the amature mycologist.