Hi Chris
If you are looking at Solar then the best product on the market is GoalZero and Powertraveller. Unfortunately with the best solar technology the price is quite steep. My suggestion would be the Powertraveller Extreme Solar which can be used to directly charge your units from the solar charger but that is only the solar charger which costs about R1299. You would then also still need a powerbank to store the energy and that comes as the Powertraveller Extreme package which retails for about R2499. The downside to solar is that it is not yet as lightweight and small as the powerbanks where you just charge it and then use it and it runs out.
On the GoalZero side you will be looking at the Nomad 7 Plus which can also be used to charge directly from the sun into a USB device. To be able to charge your phone and GPS etc you will look at the Guide 10 plus solar for about R2199.
Otherwise you can look at any other regular powerbank like Red-E, Romoss or GoalZero on the market.
Hope this helps.