I am going to toss another monkey in here. You want to keep in touch with folks via email. I cannot help with surfing the web (you might be best served with cellular connectivity there.) As for social media posting I might suggest when many folks seem to do. When write lots of blogs and take pictures and video and then store them in an external hard drive for uploading at internet cafe's along the route. You can plan your trip to these cafe's around resupply runs into population centers.
There is something thing I can help with: email and letting people know you are ok.
First you need your ham radio license at a General, but preferably Amateur Extra class level. (The Extra license makes it easier to do reciprocity in some places but the General may do. You need to research on a country by county basis. I can give you some help on this if you go this route.)
Next you need a station capable of Voice and Data communications. I'd offer simplicity and reliability are high on your list here so look at a Kenwood TS-480 radio. A solid multiband antenna like a screwdriver antenna such as a Hi-Q, Tarheel, or Scorpion (a Hustler with separate resonators is a good back-up) is next. Finally I'd suggest an SCS modem the cheapest and simplest one for what I am thinking is this:
http://www.p4dragon.com/en/Modems.html#widget4 (with a GPS hockey puck interfaced.)
This set up will give you the following:
1) Voice nets on HF which reach far beyond VHF capabilities. Including reach back to the USA when outside the country.
2) WINLINK email. Mariners and people who do emergency communications use this system. You can learn more here:
https://www.winlink.org/
3) HF APRS. This is a position tracking system. When you are not talking on the radio you can beacon your position using one of a few different modes. When heard, your GPS position is posted up on the internet and easily found by folks back home. One version of HF APRS is here:
http://wa8lmf.net/APRS_PSK63/index.htm and another approach is here:
http://robust-packet.net/ both approaches work.
This will be cheaper in the long run. More flexible in the long run. More fun in the long run perhaps.
Just my 2 cents.