If you really like what you're finding but it requires something besides 12v dc (or whatever your battery bank's voltage may be), know that dc-dc conversion is easy. Search Amazon for "dc-dc buck" or "dc-dc boost" for voltage down- and up-converters respectively. There are also some "buck-boost" which can convert both up and down.
I'm looking forward to receiving in the next few days this $21 100W step-up converter, with both constant-voltage and constant-current operation
which I'll use to drive this $10 absurdly bright 100W LED module
. The module operates in the neighborhood of 30-34 volts, and the power supply converts 3-35 V input (ie, my 12 volt) to 3-35 V output. Haven't figured out yet exactly where or how it'll fit into the bus project, among other things, but surely I'll come up with something after playing with it!
Those converters on Amazon are relatively inexpensive, but potentially cheaply built too. A place like Powerstream
sells a variety of dc-dc converters that are probably more rugged, come in a nice housing, may have higher power ratings, but unfortunately do cost more.