Simple IOT project, what network to use?

I am trying to make a simple remote measurement device. It will be a few hundred miles away and I want to see the data it has gathered every day or so and occasionally send it a short command.

I can send data to Phant on easily but I don't see an easy way to send commands to the Arduino using Phant.

I tried ATT's M2X with a developer account and I can send two streams of data from the Arduino to the M2X web page most of the time, but it seems to go out for hours periodically. It looks to be easy to post a command to the M2X page and have the Arduino poll for it but I can't seem to get that to work.

Is there some other method that I should look at? It seems like a common task in the world of IOT everything but it is giving me real problems.

I am using an Arduino Uno with a Sparkfun CC3000 WiFi shield.

There are considerations like economics and the amount of traffic, but what you are talking about maybe a bit of overkill for IoT and it could a lot simpler to use two-way text messages by GSM shield.

I may not be able to count on cellular coverage but I do have WiFi. What would it take to send text messages to an Arduino via WiFi?

SherpaDoug: What would it take to send text messages to an Arduino via WiFi?

I'm afraid I don't know. I imagine it can be done but I'm not sure there is much point in it. The reason why I raised using a phone was that it seems easier to get a command to Arduino. I have used Xively but only for sending regular data stream for live graphic display, while you are doing something more casual, and I use it one-way - no commands back to Arduino.