I support the forum starting a list of hardware/Project available for IoT ..(day by day I will try to add news)
- Sparkfun https://www.sparkfun.com/
- Arduino https://www.arduino.cc/
- XBee https://www.digi.com/xbee
- ESP Various models (wifi projects) 8266 based or Node Base (BLE+WIFI) http://www.nodemcu.com/index_en.html
- Libelium
- Adafruit https://www.adafruit.com/
..