DIY dehumidifer Kiln - Probes, sensors and monitors

[Marshall7199]

After a bit too much lurking, I am struggling to find references to safe and dependable temperature and humidity sensors / controller...... and at a small scale kiln operation DIY price.  

I am designing a dehumidifier kiln to be used in my shed.  Initial design is a 14 ft x 4 ft x 4 ft (ish) kiln.  Plan to run a dehumidifier kiln after air drying slabs.  Ideally I would lime it to be self controlled in that the heat or dehumidifier activate automatic based on the environment in the kiln. 

Temp controllers seem plentiful and economical.  As for humidity and a moisture sensor, open to suggestions or what others are using.

As a bonus, would be nice to have some type of a WIFI setup so I could read the info from the house.  

Recommendations are welcome