tinman13kup:
Much of this has yet to be decided by YOU. You cannot design a system and then decide what to do with it. That's kind-of backwards.You have to make the decision on what the desired/required output is and balance that with the expected load that will use it, which will in turn determine the battery required, voltage, and current.
I DID indicate what the use(s) will be. Initially, to charge a USB power bank, which are standard items pretty much everyone here knows about. Later, perhaps, an Arduino--powered by said power bank. Or, if a more suitable/efficient type of battery is suggested, then THAT battery. I'm just asking if anyone can recommend a decent MPPT circuit board to use with the numbers I gave above, for these intended uses.