Thanks for the reply - the modules each draw about 100 mA*, and anywhere from 1 to 8 might be switched on at any given time. Given that the current drawn increases rather quickly at and above a 14 volt input, I believe each module consists of 3 LEDs and a limiting resistor, all in series, something like the “12 volt” example here:
https://www.waveformlighting.com/pcb-designs/led-strip-light-schematic-and-voltage-information
*Exactly what LED is used I am not sure. It is apparently something a bit “less” than a 2835, as the 2835 is rated at a maximum 150 mA, not 100 mA. (At 150 mA these modules get awfully hot awfully quickly. But they seem fine, just a bit warm, @ 100 mA.)
More, in a bit...
Then I would go on eBay and look for what is called an “open frame” power supply. There are about fifty companies that make these, they are ubiquitous. Sola, Condor. Power-one, Lambda. Super reliable. I would prefer a linear supply. If you can handle that exposed wire format.
You should be able to find something for under twenty five dollars delivered, Possibly brand new in the box. 100x easier than building one.