Certainly you don't need to buy any particular brand.
But, it is good to be realisitic about what can be run from a small solar module. A 10 watt module will only produce about 0.5 amp under full sun conditions, or about 2-3 amphours a day on a good day. That likely won't even maintain an rPod's battery supplying the typical parasitic loads in the trailer over the long term.
OTOH, if you start out with a fully charged battery and are conservative you can go many days without needing to recharge at all, in which case having a charging source while boondocking might be uneccesary.
It depends on what you want to be able to run in your trailer,the led lights are usually the smallest load. The furnace, fantastic fan, TV, etc are much more significant.