The 5 Volt might be best done as 10Pcs Dual USB Output 6-24V To 5.2V 3A DC-DC Step Down Power Charger Module Converter.
The 19.5 Volt
I have a raw 26.X volt system derived from two sets of lead acid in series.
This system is rough and unbalanced and will require refinement.
One leg relies on the AGM UPS batteries and the bulk of the solar panels. This system also supplies all the 12 volts for everything.
The other leg is a spare car battery which was used for starting the petrol genset before I got rid of it. There is a single solar panel spare which I manually switch in to charge it and MUST remember to disconnect it.
Bangood DC-DC CC CV Buck Converter Board Step Down Power Supply Module 7-32V to 0.8-28V 12A
A decent set of speakers will finish the job nicely. Wireless speakers would be cool.