Hi gopherguy13,
No Wi-Fi is ok as long as you have cell data access for your mobile device. I'd recommend using the ISY controller to control your INSTEON devices including your INSTEON thermostat. The ISY plugs into the network router on site for network/internet access. The ISY is not a Wi-Fi device and needs an ethernet cable to your network.
Since you are just starting out, here's our starter kit (with a video showing how it all hook up):
http://mobilincstore.com/starter-kits/b ... r-kit.htmlAny additional parts you add to your order you'll automatically get 5% off with the purchase of our starter kit.
For your thermostat, here's the thermostat we recommend:
http://mobilincstore.com/thermostats/in ... ostat.htmlPlease let me know if you have any other questions.
Wes