The easiest power supply in the world is to get a deep cycle battery and a trickle charger. (The battery linked is a great one but it’s pricey.) I would then build a very small solar system to keep it charged if the grid goes down. (Renogy 100w Solar Panel for $150 and a Sunforce 30A Charge Controller for $75) When you can afford to, get something like a Yaesu FT-857D and you will have worldwide communication.
Edit: I added a post over in Hands On Projects about a much more capable solar system.