Upright freezer with a dual stage ranco-type controller. Volume-wise it's much larger than needed, but the next size down wouldn't have had enough height. The probe, an NTC thermistor, is taped to the side under insulation. This works great for measurement, but has to be un-taped each batch as I need to take the whole thing out for cleaning. There's an extra ferrule for my thermowell, but it's on other equipment at the moment. Heater is an incandescent bulb. There's a fan on all the time to keep the air, and hence the beer, from stratifying. This is actually quite important according to my tests without it. Spunding valve works as you think it might, but It's a pain to clean that whole attachment. I'm also paranoid about krausen clogging it. The good news is that I mostly do lagers, and even with ales, a few psi really keeps the foam down. Thinking about separating it from the main conical with a large, clear piece of tubing. That way I can see if it's foaming over before it gets to the valve. There's an aux port with a flare fitting so I can attach CO2 to keep some positive pressure when crash chilling. There are coils in the ceiling of these things, so be careful when drilling through the top. It's on a 2x4 frame on casters, so I can move it closer to the kettle for filling with chilled wort.
Overall I'm quite happy with it. On batch three now. Was supposed to be a Dortmunder Export but the gravity came in way high at 1.066, so I guess it's going to be a bock of some sort.
Wouldn't take much to be able to control the humidity for meat curing and drying.