I have decided on the radio I will use.  I plan on using the ESP8266 ESP12 WiFi module.  In the last few months, the maker community has made a lot of progress with these modules.  These modules have castellated solder pins which are relatively easy to hand solder.

The lack of documentation is a bit worrysome.  I don’t know if I will need another processor or not.  So I will get one of these in and start tinkering with it. It looks like the research here is going to require physical testing and experimenting.

I have found it available at Alibaba, Adafruit, and Amazon.